diff --git a/src/Umbraco.Core/Composing/TypeLoader.cs b/src/Umbraco.Core/Composing/TypeLoader.cs
index 2b55f78860..ef72386135 100644
--- a/src/Umbraco.Core/Composing/TypeLoader.cs
+++ b/src/Umbraco.Core/Composing/TypeLoader.cs
@@ -4,14 +4,11 @@ using System.IO;
 using System.Linq;
 using System.Reflection;
 using System.Runtime.Serialization;
-using System.Text;
-using System.Threading;
 using Microsoft.Extensions.Logging;
 using Umbraco.Cms.Core.Cache;
 using Umbraco.Cms.Core.Collections;
 using Umbraco.Cms.Core.Logging;
 using Umbraco.Extensions;
-using File = System.IO.File;
 
 namespace Umbraco.Cms.Core.Composing
 {
@@ -21,112 +18,58 @@ namespace Umbraco.Cms.Core.Composing
     /// <remarks>
     /// <para>This class should be used to get all types, the <see cref="ITypeFinder"/> class should never be used directly.</para>
     /// <para>In most cases this class is not used directly but through extension methods that retrieve specific types.</para>
-    /// <para>This class caches the types it knows to avoid excessive assembly scanning and shorten startup times, relying
-    /// on a hash of the DLLs in the ~/bin folder to check for cache expiration.</para>
     /// </remarks>
     public sealed class TypeLoader
     {
-        private readonly IRuntimeHash _runtimeHash;
-        private readonly IAppPolicyCache _runtimeCache;
         private readonly ILogger<TypeLoader> _logger;
-        private readonly IProfilingLogger _profilingLogger;
 
-        private readonly Dictionary<CompositeTypeTypeKey, TypeList> _types = new Dictionary<CompositeTypeTypeKey, TypeList>();
-        private readonly object _locko = new object();
-        private readonly object _timerLock = new object();
+        private readonly Dictionary<CompositeTypeTypeKey, TypeList> _types = new ();
+        private readonly object _locko = new ();
 
-        private Timer? _timer;
-        private bool _timing;
-        private string? _cachedAssembliesHash;
-        private string? _currentAssembliesHash;
-        private IEnumerable<Assembly>? _assemblies;
-        private bool _reportedChange;
-        private readonly DirectoryInfo _localTempPath;
-        private readonly Lazy<string?> _fileBasePath;
-        private readonly Dictionary<(string, string), IEnumerable<string>> _emptyCache = new Dictionary<(string, string), IEnumerable<string>>();
-        private string? _typesListFilePath;
-        private string? _typesHashFilePath;
+        private IEnumerable<Assembly> _assemblies;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="TypeLoader"/> class.
         /// </summary>
-        /// <param name="typeFinder"></param>
-        /// <param name="runtimeCache">The application runtime cache.</param>
-        /// <param name="localTempPath">Files storage location.</param>
-        /// <param name="logger">A profiling logger.</param>
-        /// <param name="assembliesToScan"></param>
-        public TypeLoader(ITypeFinder typeFinder, IRuntimeHash runtimeHash, IAppPolicyCache runtimeCache, DirectoryInfo localTempPath, ILogger<TypeLoader> logger, IProfiler profiler, IEnumerable<Assembly>? assembliesToScan = null)
-            : this(typeFinder, runtimeHash, runtimeCache, localTempPath, logger, profiler, true, assembliesToScan)
-        { }
-
-        /// <summary>
-        /// Initializes a new instance of the <see cref="TypeLoader"/> class.
-        /// </summary>
-        /// <param name="typeFinder"></param>
-        /// <param name="runtimeCache">The application runtime cache.</param>
-        /// <param name="localTempPath">Files storage location.</param>
-        /// <param name="logger">A profiling logger.</param>
-        /// <param name="detectChanges">Whether to detect changes using hashes.</param>
-        /// <param name="assembliesToScan"></param>
-        public TypeLoader(ITypeFinder typeFinder, IRuntimeHash runtimeHash, IAppPolicyCache runtimeCache, DirectoryInfo localTempPath, ILogger<TypeLoader> logger, IProfiler profiler, bool detectChanges, IEnumerable<Assembly>? assembliesToScan = null)
+        [Obsolete("Please use an alternative constructor.")]
+        public TypeLoader(
+            ITypeFinder typeFinder,
+            IRuntimeHash runtimeHash,
+            IAppPolicyCache runtimeCache,
+            DirectoryInfo localTempPath,
+            ILogger<TypeLoader> logger,
+            IProfiler profiler,
+            IEnumerable<Assembly>? assembliesToScan = null)
+            : this(typeFinder, logger, assembliesToScan)
         {
-            if (profiler is null)
-            {
-                throw new ArgumentNullException(nameof(profiler));
-            }
-
-            var runtimeHashValue = runtimeHash.GetHashValue();
-            CacheKey = runtimeHashValue + "umbraco-types.list";
-
-            TypeFinder = typeFinder ?? throw new ArgumentNullException(nameof(typeFinder));
-            _runtimeHash = runtimeHash;
-            _runtimeCache = runtimeCache ?? throw new ArgumentNullException(nameof(runtimeCache));
-            _localTempPath = localTempPath;
-            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
-            _profilingLogger = new ProfilingLogger(logger, profiler);
-            _assemblies = assembliesToScan;
-
-            _fileBasePath = new Lazy<string?>(GetFileBasePath);
-
-            if (detectChanges)
-            {
-                //first check if the cached hash is string.Empty, if it is then we need
-                //do the check if they've changed
-                RequiresRescanning = CachedAssembliesHash != CurrentAssembliesHash || CachedAssembliesHash == string.Empty;
-                //if they have changed, we need to write the new file
-                if (RequiresRescanning)
-                {
-                    _logger.LogDebug("Plugin types are being re-scanned. Cached hash value: {CachedHash}, Current hash value: {CurrentHash}", CachedAssembliesHash, CurrentAssembliesHash);
-
-                    // if the hash has changed, clear out the persisted list no matter what, this will force
-                    // rescanning of all types including lazy ones.
-                    // http://issues.umbraco.org/issue/U4-4789
-                    var typesListFilePath = GetTypesListFilePath();
-                    if (typesListFilePath != null)
-                    {
-                        DeleteFile(typesListFilePath, FileDeleteTimeout);
-                    }
-
-                    WriteCacheTypesHash();
-                }
-            }
-            else
-            {
-                // if the hash has changed, clear out the persisted list no matter what, this will force
-                // rescanning of all types including lazy ones.
-                // http://issues.umbraco.org/issue/U4-4789
-                var typesListFilePath = GetTypesListFilePath();
-                if (typesListFilePath != null)
-                {
-                    DeleteFile(typesListFilePath, FileDeleteTimeout);
-                }
-
-                // always set to true if we're not detecting (generally only for testing)
-                RequiresRescanning = true;
-            }
         }
 
-        internal string CacheKey { get; }
+        /// <summary>
+        /// Initializes a new instance of the <see cref="TypeLoader"/> class.
+        /// </summary>
+        [Obsolete("Please use an alternative constructor.")]
+        public TypeLoader(
+            ITypeFinder typeFinder,
+            IRuntimeHash runtimeHash,
+            IAppPolicyCache runtimeCache,
+            DirectoryInfo localTempPath,
+            ILogger<TypeLoader> logger,
+            IProfiler profiler,
+            bool detectChanges,
+            IEnumerable<Assembly>? assembliesToScan = null)
+            : this(typeFinder, logger, assembliesToScan)
+        {
+        }
+
+        public TypeLoader(
+            ITypeFinder typeFinder,
+            ILogger<TypeLoader> logger,
+            IEnumerable<Assembly>? assembliesToScan = null)
+        {
+            TypeFinder = typeFinder ?? throw new ArgumentNullException(nameof(typeFinder));
+            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+            _assemblies = assembliesToScan;
+        }
 
         /// <summary>
         /// Returns the underlying <see cref="ITypeFinder"/>
@@ -144,6 +87,7 @@ namespace Umbraco.Cms.Core.Composing
         /// <para>This is for unit tests.</para>
         /// </remarks>
         // internal for tests
+        [Obsolete("This will be removed in a future version.")]
         public IEnumerable<Assembly> AssembliesToScan => _assemblies ??= TypeFinder.AssembliesToScan;
 
         /// <summary>
@@ -151,6 +95,7 @@ namespace Umbraco.Cms.Core.Composing
         /// </summary>
         /// <remarks>For unit tests.</remarks>
         // internal for tests
+        [Obsolete("This will be removed in a future version.")]
         public IEnumerable<TypeList> TypeLists => _types.Values;
 
         /// <summary>
@@ -158,378 +103,49 @@ namespace Umbraco.Cms.Core.Composing
         /// </summary>
         /// <remarks>For unit tests.</remarks>
         // internal for tests
+        [Obsolete("This will be removed in a future version.")]
         public void AddTypeList(TypeList typeList)
         {
             var tobject = typeof(object); // CompositeTypeTypeKey does not support null values
             _types[new CompositeTypeTypeKey(typeList.BaseType ?? tobject, typeList.AttributeType ?? tobject)] = typeList;
         }
 
-        #region Hashing
-
-        /// <summary>
-        /// Gets a value indicating whether the assemblies in bin, app_code, global.asax, etc... have changed since they were last hashed.
-        /// </summary>
-        private bool RequiresRescanning { get; }
-
-        /// <summary>
-        /// Gets the currently cached hash value of the scanned assemblies.
-        /// </summary>
-        /// <value>The cached hash value, or string.Empty if no cache is found.</value>
-        internal string CachedAssembliesHash
-        {
-            get
-            {
-                if (_cachedAssembliesHash != null)
-                {
-                    return _cachedAssembliesHash;
-                }
-
-                var typesHashFilePath = GetTypesHashFilePath();
-                if (typesHashFilePath == null)
-                {
-                    return string.Empty;
-                }
-
-                if (!File.Exists(typesHashFilePath))
-                {
-                    return string.Empty;
-                }
-
-                var hash = File.ReadAllText(typesHashFilePath, Encoding.UTF8);
-
-                _cachedAssembliesHash = hash;
-                return _cachedAssembliesHash;
-            }
-        }
-
-        /// <summary>
-        /// Gets the current assemblies hash based on creating a hash from the assemblies in various places.
-        /// </summary>
-        /// <value>The current hash.</value>
-        private string CurrentAssembliesHash
-        {
-            get
-            {
-                if (_currentAssembliesHash != null)
-                {
-                    return _currentAssembliesHash;
-                }
-
-                _currentAssembliesHash = _runtimeHash.GetHashValue();
-
-                return _currentAssembliesHash;
-            }
-        }
-
-        /// <summary>
-        /// Writes the assembly hash file.
-        /// </summary>
-        private void WriteCacheTypesHash()
-        {
-            var typesHashFilePath = GetTypesHashFilePath();
-            if (typesHashFilePath != null)
-            {
-                File.WriteAllText(typesHashFilePath, CurrentAssembliesHash, Encoding.UTF8);
-            }
-        }
-
-        #endregion
-
         #region Cache
 
-        private const int ListFileOpenReadTimeout = 4000; // milliseconds
-        private const int ListFileOpenWriteTimeout = 2000; // milliseconds
-        private const int ListFileWriteThrottle = 500; // milliseconds - throttle before writing
-        private const int ListFileCacheDuration = 2 * 60; // seconds - duration we cache the entire list
-        private const int FileDeleteTimeout = 4000; // milliseconds
-
         // internal for tests
-        public Attempt<IEnumerable<string>?> TryGetCached(Type? baseType, Type? attributeType)
+        [Obsolete("This will be removed in a future version.")]
+        public Attempt<IEnumerable<string>> TryGetCached(Type baseType, Type attributeType)
         {
-            var cache =
-                _runtimeCache.GetCacheItem(CacheKey, ReadCacheSafe, TimeSpan.FromSeconds(ListFileCacheDuration))!;
-
-            cache.TryGetValue(
-                (baseType == null ? string.Empty : baseType.FullName ?? string.Empty, attributeType == null ? string.Empty : attributeType.FullName ?? string.Empty),
-                out IEnumerable<string>? types);
-
-            return types == null
-                ? Attempt<IEnumerable<string>?>.Fail()
-                : Attempt.Succeed(types);
-        }
-
-        private Dictionary<(string, string), IEnumerable<string>> ReadCacheSafe()
-        {
-            try
-            {
-                return ReadCache();
-            }
-            catch
-            {
-                try
-                {
-                    var typesListFilePath = GetTypesListFilePath();
-                    if (typesListFilePath != null)
-                    {
-                        DeleteFile(typesListFilePath, FileDeleteTimeout);
-                    }
-                }
-                catch
-                {
-                    // on-purpose, does not matter
-                }
-            }
-
-            return _emptyCache;
+            return Attempt<IEnumerable<string>>.Fail();
         }
 
         // internal for tests
-        public Dictionary<(string, string), IEnumerable<string>> ReadCache()
-        {
-            var typesListFilePath = GetTypesListFilePath();
-            if (typesListFilePath == null || File.Exists(typesListFilePath) == false)
-            {
-                return _emptyCache;
-            }
-
-            var cache = new Dictionary<(string, string), IEnumerable<string>>();
-            using (var stream = GetFileStream(typesListFilePath, FileMode.Open, FileAccess.Read, FileShare.Read, ListFileOpenReadTimeout))
-            using (var reader = new StreamReader(stream))
-            {
-                while (true)
-                {
-                    var baseType = reader.ReadLine();
-                    if (baseType == null)
-                    {
-                        return cache; // exit
-                    }
-
-                    if (baseType.StartsWith("<"))
-                    {
-                        break; // old xml
-                    }
-
-                    var attributeType = reader.ReadLine();
-                    if (attributeType == null)
-                    {
-                        break;
-                    }
-
-                    var types = new List<string>();
-                    while (true)
-                    {
-                        var type = reader.ReadLine();
-                        if (type == null)
-                        {
-                            types = null; // break 2 levels
-                            break;
-                        }
-                        if (type == string.Empty)
-                        {
-                            cache[(baseType, attributeType)] = types;
-                            break;
-                        }
-                        types.Add(type);
-                    }
-
-                    if (types == null)
-                    {
-                        break;
-                    }
-                }
-            }
-
-            cache.Clear();
-            return cache;
-        }
+        [Obsolete("This will be removed in a future version.")]
+        public Dictionary<(string, string), IEnumerable<string>> ReadCache() => null;
 
         // internal for tests
-        public string? GetTypesListFilePath() => _typesListFilePath ??= _fileBasePath.Value == null ? null : _fileBasePath.Value + ".list";
-
-        private string? GetTypesHashFilePath() => _typesHashFilePath ??= _fileBasePath.Value == null ? null : _fileBasePath.Value + ".hash";
-
-        /// <summary>
-        /// Used to produce the Lazy value of _fileBasePath
-        /// </summary>
-        /// <returns></returns>
-        private string? GetFileBasePath()
-        {
-            if (_localTempPath == null)
-            {
-                return null;
-            }
-
-            var fileBasePath = Path.Combine(_localTempPath.FullName, "TypesCache", "umbraco-types." + EnvironmentHelper.FileSafeMachineName);
-
-            // ensure that the folder exists
-            var directory = Path.GetDirectoryName(fileBasePath);
-            if (directory == null)
-            {
-                throw new InvalidOperationException($"Could not determine folder for path \"{fileBasePath}\".");
-            }
-
-            if (Directory.Exists(directory) == false)
-            {
-                Directory.CreateDirectory(directory);
-            }
-
-            return fileBasePath;
-        }
+        [Obsolete("This will be removed in a future version.")]
+        public string GetTypesListFilePath() => null;
 
         // internal for tests
+        [Obsolete("This will be removed in a future version.")]
         public void WriteCache()
         {
-            _logger.LogDebug("Writing cache file.");
-            var typesListFilePath = GetTypesListFilePath();
-            if (typesListFilePath == null)
-            {
-                return;
-            }
-
-            using (var stream = GetFileStream(typesListFilePath, FileMode.Create, FileAccess.Write, FileShare.None, ListFileOpenWriteTimeout))
-            using (var writer = new StreamWriter(stream))
-            {
-                foreach (var typeList in _types.Values)
-                {
-                    writer.WriteLine(typeList.BaseType == null ? string.Empty : typeList.BaseType.FullName);
-                    writer.WriteLine(typeList.AttributeType == null ? string.Empty : typeList.AttributeType.FullName);
-                    foreach (var type in typeList.Types)
-                    {
-                        writer.WriteLine(type.AssemblyQualifiedName);
-                    }
-
-                    writer.WriteLine();
-                }
-            }
-        }
-
-        // internal for tests
-        internal void UpdateCache()
-        {
-            void TimerRelease(object? o)
-            {
-                lock (_timerLock)
-                {
-                    try
-                    {
-                        WriteCache();
-                    }
-                    catch { /* bah - just don't die */ }
-                    if (!_timing)
-                        _timer = null;
-                }
-            }
-
-            lock (_timerLock)
-            {
-                if (_timer == null)
-                {
-                    _timer = new Timer(TimerRelease, null, ListFileWriteThrottle, Timeout.Infinite);
-                }
-                else
-                {
-                    _timer.Change(ListFileWriteThrottle, Timeout.Infinite);
-                }
-
-                _timing = true;
-            }
         }
 
         /// <summary>
-        /// Removes cache files and internal cache.
+        /// Clears cache.
         /// </summary>
         /// <remarks>Generally only used for resetting cache, for example during the install process.</remarks>
+        [Obsolete("This will be removed in a future version.")]
         public void ClearTypesCache()
         {
-            var typesListFilePath = GetTypesListFilePath();
-            if (typesListFilePath == null)
-            {
-                return;
-            }
-
-            DeleteFile(typesListFilePath, FileDeleteTimeout);
-
-            var typesHashFilePath = GetTypesHashFilePath();
-            if (typesHashFilePath != null)
-            {
-                DeleteFile(typesHashFilePath, FileDeleteTimeout);
-            }
-
-            _runtimeCache.Clear(CacheKey);
-        }
-
-        private Stream GetFileStream(string path, FileMode fileMode, FileAccess fileAccess, FileShare fileShare, int timeoutMilliseconds)
-        {
-            const int pauseMilliseconds = 250;
-            var attempts = timeoutMilliseconds / pauseMilliseconds;
-            while (true)
-            {
-                try
-                {
-                    return new FileStream(path, fileMode, fileAccess, fileShare);
-                }
-                catch
-                {
-                    if (--attempts == 0)
-                    {
-                        throw;
-                    }
-
-                    _logger.LogDebug("Attempted to get filestream for file {Path} failed, {NumberOfAttempts} attempts left, pausing for {PauseMilliseconds} milliseconds", path, attempts, pauseMilliseconds);
-                    Thread.Sleep(pauseMilliseconds);
-                }
-            }
-        }
-
-        private void DeleteFile(string path, int timeoutMilliseconds)
-        {
-            const int pauseMilliseconds = 250;
-            var attempts = timeoutMilliseconds / pauseMilliseconds;
-            while (File.Exists(path))
-            {
-                try
-                {
-                    File.Delete(path);
-                }
-                catch
-                {
-                    if (--attempts == 0)
-                        throw;
-
-                    _logger.LogDebug("Attempted to delete file {Path} failed, {NumberOfAttempts} attempts left, pausing for {PauseMilliseconds} milliseconds", path, attempts, pauseMilliseconds);
-                    Thread.Sleep(pauseMilliseconds);
-                }
-            }
         }
 
         #endregion
 
         #region Get Assembly Attributes
 
-        ///// <summary>
-        ///// Gets the assembly attributes of the specified type <typeparamref name="T" />.
-        ///// </summary>
-        ///// <typeparam name="T">The attribute type.</typeparam>
-        ///// <returns>
-        ///// The assembly attributes of the specified type <typeparamref name="T" />.
-        ///// </returns>
-        //public IEnumerable<T> GetAssemblyAttributes<T>()
-        //    where T : Attribute
-        //{
-        //    return AssembliesToScan.SelectMany(a => a.GetCustomAttributes<T>()).ToList();
-        //}
-
-        ///// <summary>
-        ///// Gets all the assembly attributes.
-        ///// </summary>
-        ///// <returns>
-        ///// All assembly attributes.
-        ///// </returns>
-        //public IEnumerable<Attribute> GetAssemblyAttributes()
-        //{
-        //    return AssembliesToScan.SelectMany(a => a.GetCustomAttributes()).ToList();
-        //}
-
         /// <summary>
         /// Gets the assembly attributes of the specified <paramref name="attributeTypes" />.
         /// </summary>
@@ -701,17 +317,9 @@ namespace Umbraco.Cms.Core.Composing
             // loader is mostly not going to be used in any kind of massively multi-threaded scenario - so,
             // a plain lock is enough
 
-            var name = GetName(baseType, attributeType);
-
             lock (_locko)
             {
-                using (_profilingLogger.DebugDuration<TypeLoader>(
-                "Getting " + name,
-                "Got " + name)) // cannot contain typesFound.Count as it's evaluated before the find
-                {
-                    // get within a lock & timer
-                    return GetTypesInternalLocked(baseType, attributeType, finder, action, cache);
-                }
+                return GetTypesInternalLocked(baseType, attributeType, finder, action, cache);
             }
         }
 
@@ -731,9 +339,9 @@ namespace Umbraco.Cms.Core.Composing
         {
             // check if the TypeList already exists, if so return it, if not we'll create it
             var tobject = typeof(object); // CompositeTypeTypeKey does not support null values
-
             var listKey = new CompositeTypeTypeKey(baseType ?? tobject, attributeType ?? tobject);
-            TypeList? typeList = null;
+            TypeList typeList = null;
+
             if (cache)
             {
                 _types.TryGetValue(listKey, out typeList); // else null
@@ -750,68 +358,12 @@ namespace Umbraco.Cms.Core.Composing
             // else proceed,
             typeList = new TypeList(baseType, attributeType);
 
-            var typesListFilePath = GetTypesListFilePath();
-            var scan = RequiresRescanning || typesListFilePath == null || File.Exists(typesListFilePath) == false;
+            // either we had to scan, or we could not get the types from the cache file - scan now
+            _logger.LogDebug("Getting {TypeName}: " + action + ".", GetName(baseType, attributeType));
 
-            if (scan)
+            foreach (var t in finder())
             {
-                // either we have to rescan, or we could not find the cache file:
-                // report (only once) and scan and update the cache file
-                if (_reportedChange == false)
-                {
-                    _logger.LogDebug("Assemblies changes detected, need to rescan everything.");
-                    _reportedChange = true;
-                }
-            }
-
-            if (scan == false)
-            {
-                // if we don't have to scan, try the cache
-                var cacheResult = TryGetCached(baseType, attributeType);
-
-                // here we need to identify if the CachedTypeNotFoundInFile was the exception, if it was then we need to re-scan
-                // in some cases the type will not have been scanned for on application startup, but the assemblies haven't changed
-                // so in this instance there will never be a result.
-                if (cacheResult.Exception is CachedTypeNotFoundInFileException || cacheResult.Success == false)
-                {
-                    _logger.LogDebug("Getting {TypeName}: failed to load from cache file, must scan assemblies.", GetName(baseType, attributeType));
-                    scan = true;
-                }
-                else
-                {
-                    // successfully retrieved types from the file cache: load
-                    foreach (var type in cacheResult.Result!)
-                    {
-                        var resolvedType = TypeFinder.GetTypeByName(type);
-                        if (resolvedType != null)
-                        {
-                            typeList.Add(resolvedType);
-                        }
-                        else
-                        {
-                            // in case of any exception, we have to exit, and revert to scanning
-                            _logger.LogWarning("Getting {TypeName}: failed to load cache file type {CacheType}, reverting to scanning assemblies.", GetName(baseType, attributeType), type);
-                            scan = true;
-                            break;
-                        }
-                    }
-
-                    if (scan == false)
-                    {
-                        _logger.LogDebug("Getting {TypeName}: loaded types from cache file.", GetName(baseType, attributeType));
-                    }
-                }
-            }
-
-            if (scan)
-            {
-                // either we had to scan, or we could not get the types from the cache file - scan now
-                _logger.LogDebug("Getting {TypeName}: " + action + ".", GetName(baseType, attributeType));
-
-                foreach (var t in finder())
-                {
-                    typeList.Add(t);
-                }
+                typeList.Add(t);
             }
 
             // if we are to cache the results, do so
@@ -821,11 +373,6 @@ namespace Umbraco.Cms.Core.Composing
                 if (added)
                 {
                     _types[listKey] = typeList;
-                    //if we are scanning then update the cache file
-                    if (scan)
-                    {
-                        UpdateCache();
-                    }
                 }
 
                 _logger.LogDebug("Got {TypeName}, caching ({CacheType}).", GetName(baseType, attributeType), added.ToString().ToLowerInvariant());
@@ -864,7 +411,7 @@ namespace Umbraco.Cms.Core.Composing
             /// </summary>
             public void Add(Type type)
             {
-                if (BaseType?.IsAssignableFrom(type) == false)
+                if (BaseType.IsAssignableFrom(type) == false)
                     throw new ArgumentException("Base type " + BaseType + " is not assignable from type " + type + ".", nameof(type));
                 _types.Add(type);
             }
diff --git a/src/Umbraco.Core/DependencyInjection/IUmbracoBuilder.cs b/src/Umbraco.Core/DependencyInjection/IUmbracoBuilder.cs
index 02b356a244..521f55dbef 100644
--- a/src/Umbraco.Core/DependencyInjection/IUmbracoBuilder.cs
+++ b/src/Umbraco.Core/DependencyInjection/IUmbracoBuilder.cs
@@ -1,3 +1,4 @@
+using System;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
@@ -27,6 +28,7 @@ namespace Umbraco.Cms.Core.DependencyInjection
         /// <remarks>
         /// This may be null.
         /// </remarks>
+        [Obsolete("This property will be removed in a future version, please find an alternative approach.")]
         IHostingEnvironment? BuilderHostingEnvironment { get; }
 
         IProfiler Profiler { get; }
diff --git a/src/Umbraco.Core/Extensions/HostEnvironmentExtensions.cs b/src/Umbraco.Core/Extensions/HostEnvironmentExtensions.cs
new file mode 100644
index 0000000000..658739ba93
--- /dev/null
+++ b/src/Umbraco.Core/Extensions/HostEnvironmentExtensions.cs
@@ -0,0 +1,53 @@
+using System;
+using System.IO;
+using Microsoft.Extensions.Hosting;
+using Umbraco.Extensions;
+
+namespace Umbraco.Cms.Core.Extensions
+{
+    /// <summary>
+    /// Contains extension methods for the <see cref="IHostEnvironment" /> interface.
+    /// </summary>
+    public static class HostEnvironmentExtensions
+    {
+        private static string s_temporaryApplicationId;
+
+        /// <summary>
+        /// Maps a virtual path to a physical path to the application's content root.
+        /// </summary>
+        /// <remarks>
+        /// Generally the content root is the parent directory of the web root directory.
+        /// </remarks>
+        public static string MapPathContentRoot(this IHostEnvironment hostEnvironment, string path)
+        {
+            var root = hostEnvironment.ContentRootPath;
+
+            var newPath = path.Replace('/', Path.DirectorySeparatorChar).Replace('\\', Path.DirectorySeparatorChar);
+
+            // TODO: This is a temporary error because we switched from IOHelper.MapPath to HostingEnvironment.MapPathXXX
+            // IOHelper would check if the path passed in started with the root, and not prepend the root again if it did,
+            // however if you are requesting a path be mapped, it should always assume the path is relative to the root, not
+            // absolute in the file system.  This error will help us find and fix improper uses, and should be removed once
+            // all those uses have been found and fixed
+            if (newPath.StartsWith(root))
+            {
+                throw new ArgumentException("The path appears to already be fully qualified.  Please remove the call to MapPathContentRoot");
+            }
+
+            return Path.Combine(root, newPath.TrimStart(Constants.CharArrays.TildeForwardSlashBackSlash));
+        }
+
+        /// <summary>
+        /// Gets a temporary application id for use before the ioc container is built.
+        /// </summary>
+        public static string GetTemporaryApplicationId(this IHostEnvironment hostEnvironment)
+        {
+            if (s_temporaryApplicationId != null)
+            {
+                return s_temporaryApplicationId;
+            }
+
+            return s_temporaryApplicationId = hostEnvironment.ContentRootPath.GenerateHash();
+        }
+    }
+}
diff --git a/src/Umbraco.Core/Hosting/IHostingEnvironment.cs b/src/Umbraco.Core/Hosting/IHostingEnvironment.cs
index 5b761211ac..c2c7cfe792 100644
--- a/src/Umbraco.Core/Hosting/IHostingEnvironment.cs
+++ b/src/Umbraco.Core/Hosting/IHostingEnvironment.cs
@@ -15,12 +15,21 @@ namespace Umbraco.Cms.Core.Hosting
         /// between restarts of that Umbraco website/application on that specific server.
         /// </para>
         /// <para>
-        /// The value of this does not necesarily distinguish between unique workers/servers for this Umbraco application.
+        /// The value of this does not distinguish between unique workers/servers for this Umbraco application.
         /// Usage of this must take into account that the same <see cref="ApplicationId"/> may be returned for the same
-        /// Umbraco website hosted on different servers. Similarly the usage of this must take into account that a different
+        /// Umbraco website hosted on different servers.<br/>
+        /// Similarly the usage of this must take into account that a different
         /// <see cref="ApplicationId"/> may be returned for the same Umbraco website hosted on different servers.
         /// </para>
+        /// <para>
+        /// This returns a hash of the value of IApplicationDiscriminator.Discriminator (which is most likely just the value of <see cref=" Microsoft.Extensions.Hosting.IHostEnvironment.ContentRootPath"/> unless an alternative implementation of IApplicationDiscriminator has been registered).<br/>
+        /// However during ConfigureServices a temporary instance of IHostingEnvironment is constructed which guarantees that this will be the hash of <see cref=" Microsoft.Extensions.Hosting.IHostEnvironment.ContentRootPath"/>, so the value may differ depend on when the property is used.
+        /// </para>
+        /// <para>
+        /// If you require this value during ConfigureServices it is probably a code smell.
+        /// </para>
         /// </remarks>
+        [Obsolete("Please use IApplicationDiscriminator.Discriminator instead.")]
         string ApplicationId { get; }
 
         /// <summary>
@@ -58,6 +67,7 @@ namespace Umbraco.Cms.Core.Hosting
         /// Depending on the runtime 'web root', this result can vary. For example in Net Framework the web root and the content root are the same, however
         /// in netcore the web root is /www therefore this will Map to a physical path within www.
         /// </remarks>
+        [Obsolete("Please use the MapPathWebRoot extension method on an instance of IWebHostEnvironment instead")]
         string MapPathWebRoot(string path);
 
         /// <summary>
@@ -67,6 +77,7 @@ namespace Umbraco.Cms.Core.Hosting
         /// Depending on the runtime 'web root', this result can vary. For example in Net Framework the web root and the content root are the same, however
         /// in netcore the web root is /www therefore this will Map to a physical path within www.
         /// </remarks>
+        [Obsolete("Please use the MapPathContentRoot extension method on an instance of IHostEnvironment (or IWebHostEnvironment) instead")]
         string MapPathContentRoot(string path);
 
         /// <summary>
diff --git a/src/Umbraco.Infrastructure/Logging/Serilog/LoggerConfigExtensions.cs b/src/Umbraco.Infrastructure/Logging/Serilog/LoggerConfigExtensions.cs
index 80cbfc28d3..733410cf91 100644
--- a/src/Umbraco.Infrastructure/Logging/Serilog/LoggerConfigExtensions.cs
+++ b/src/Umbraco.Infrastructure/Logging/Serilog/LoggerConfigExtensions.cs
@@ -2,13 +2,14 @@ using System;
 using System.IO;
 using System.Text;
 using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Hosting;
 using Serilog;
 using Serilog.Configuration;
 using Serilog.Core;
 using Serilog.Events;
 using Serilog.Formatting;
 using Serilog.Formatting.Compact;
-using Umbraco.Cms.Core.Hosting;
+using Umbraco.Cms.Core.Extensions;
 using Umbraco.Cms.Core.Logging;
 using Umbraco.Cms.Core.Logging.Serilog.Enrichers;
 using Umbraco.Cms.Infrastructure.Logging.Serilog;
@@ -17,16 +18,15 @@ namespace Umbraco.Extensions
 {
     public static class LoggerConfigExtensions
     {
-        private const string AppDomainId = "AppDomainId";
-
         /// <summary>
         /// This configures Serilog with some defaults
         /// Such as adding ProcessID, Thread, AppDomain etc
         /// It is highly recommended that you keep/use this default in your own logging config customizations
         /// </summary>
+        [Obsolete("Please use an alternative method.")]
         public static LoggerConfiguration MinimalConfiguration(
             this LoggerConfiguration logConfig,
-            IHostingEnvironment hostingEnvironment,
+            Umbraco.Cms.Core.Hosting.IHostingEnvironment hostingEnvironment,
             ILoggingConfiguration loggingConfiguration,
             IConfiguration configuration)
         {
@@ -38,9 +38,10 @@ namespace Umbraco.Extensions
         /// Such as adding ProcessID, Thread, AppDomain etc
         /// It is highly recommended that you keep/use this default in your own logging config customizations
         /// </summary>
+        [Obsolete("Please use an alternative method.")]
         public static LoggerConfiguration MinimalConfiguration(
             this LoggerConfiguration logConfig,
-            IHostingEnvironment hostingEnvironment,
+            Umbraco.Cms.Core.Hosting.IHostingEnvironment hostingEnvironment,
             ILoggingConfiguration loggingConfiguration,
             IConfiguration configuration,
             out UmbracoFileConfiguration umbFileConfiguration)
@@ -49,7 +50,7 @@ namespace Umbraco.Extensions
 
             //Set this environment variable - so that it can be used in external config file
             //add key="serilog:write-to:RollingFile.pathFormat" value="%BASEDIR%\logs\log.txt" />
-            Environment.SetEnvironmentVariable("BASEDIR", hostingEnvironment.MapPathContentRoot("/").TrimEnd("\\"), EnvironmentVariableTarget.Process);
+            Environment.SetEnvironmentVariable("BASEDIR", hostingEnvironment.MapPathContentRoot("/").TrimEnd(Path.DirectorySeparatorChar), EnvironmentVariableTarget.Process);
             Environment.SetEnvironmentVariable("UMBLOGDIR", loggingConfiguration.LogDirectory, EnvironmentVariableTarget.Process);
             Environment.SetEnvironmentVariable("MACHINENAME", Environment.MachineName, EnvironmentVariableTarget.Process);
 
@@ -57,8 +58,7 @@ namespace Umbraco.Extensions
                 .Enrich.WithProcessId()
                 .Enrich.WithProcessName()
                 .Enrich.WithThreadId()
-                .Enrich.WithProperty(AppDomainId, AppDomain.CurrentDomain.Id)
-                .Enrich.WithProperty("AppDomainAppId", hostingEnvironment.ApplicationId.ReplaceNonAlphanumericChars(string.Empty))
+                .Enrich.WithProperty("ApplicationId", hostingEnvironment.ApplicationId) // Updated later by ApplicationIdEnricher
                 .Enrich.WithProperty("MachineName", Environment.MachineName)
                 .Enrich.With<Log4NetLevelMapperEnricher>()
                 .Enrich.FromLogContext(); // allows us to dynamically enrich
@@ -81,6 +81,48 @@ namespace Umbraco.Extensions
             return logConfig;
         }
 
+
+        /// <summary>
+        /// This configures Serilog with some defaults
+        /// Such as adding ProcessID, Thread, AppDomain etc
+        /// It is highly recommended that you keep/use this default in your own logging config customizations
+        /// </summary>
+        public static LoggerConfiguration MinimalConfiguration(
+            this LoggerConfiguration logConfig,
+            IHostEnvironment hostEnvironment,
+            ILoggingConfiguration loggingConfiguration,
+            UmbracoFileConfiguration umbracoFileConfiguration)
+        {
+            global::Serilog.Debugging.SelfLog.Enable(msg => System.Diagnostics.Debug.WriteLine(msg));
+
+            //Set this environment variable - so that it can be used in external config file
+            //add key="serilog:write-to:RollingFile.pathFormat" value="%BASEDIR%\logs\log.txt" />
+            Environment.SetEnvironmentVariable("BASEDIR", hostEnvironment.MapPathContentRoot("/").TrimEnd("\\"), EnvironmentVariableTarget.Process);
+            Environment.SetEnvironmentVariable("UMBLOGDIR", loggingConfiguration.LogDirectory, EnvironmentVariableTarget.Process);
+            Environment.SetEnvironmentVariable("MACHINENAME", Environment.MachineName, EnvironmentVariableTarget.Process);
+
+            logConfig.MinimumLevel.Verbose() //Set to highest level of logging (as any sinks may want to restrict it to Errors only)
+                .Enrich.WithProcessId()
+                .Enrich.WithProcessName()
+                .Enrich.WithThreadId()
+                .Enrich.WithProperty("ApplicationId", hostEnvironment.GetTemporaryApplicationId()) // Updated later by ApplicationIdEnricher
+                .Enrich.WithProperty("MachineName", Environment.MachineName)
+                .Enrich.With<Log4NetLevelMapperEnricher>()
+                .Enrich.FromLogContext(); // allows us to dynamically enrich
+
+            logConfig.WriteTo.UmbracoFile(
+                path: umbracoFileConfiguration.GetPath(loggingConfiguration.LogDirectory),
+                fileSizeLimitBytes: umbracoFileConfiguration.FileSizeLimitBytes,
+                restrictedToMinimumLevel: umbracoFileConfiguration.RestrictedToMinimumLevel,
+                rollingInterval: umbracoFileConfiguration.RollingInterval,
+                flushToDiskInterval: umbracoFileConfiguration.FlushToDiskInterval,
+                rollOnFileSizeLimit: umbracoFileConfiguration.RollOnFileSizeLimit,
+                retainedFileCountLimit: umbracoFileConfiguration.RetainedFileCountLimit
+            );
+
+            return logConfig;
+        }
+
         /// <summary>
         /// Outputs a .txt format log at /App_Data/Logs/
         /// </summary>
@@ -90,7 +132,7 @@ namespace Umbraco.Extensions
         /// <param name="retainedFileCount">The number of days to keep log files. Default is set to null which means all logs are kept</param>
         public static LoggerConfiguration OutputDefaultTextFile(
             this LoggerConfiguration logConfig,
-            IHostingEnvironment hostingEnvironment,
+            Umbraco.Cms.Core.Hosting.IHostingEnvironment hostingEnvironment,
             LogEventLevel minimumLevel = LogEventLevel.Verbose)
         {
             //Main .txt logfile - in similar format to older Log4Net output
@@ -109,7 +151,8 @@ namespace Umbraco.Extensions
         /// <remarks>
         ///    Used in config - If renamed or moved to other assembly the config file also has be updated.
         /// </remarks>
-        public static LoggerConfiguration UmbracoFile(this LoggerSinkConfiguration configuration,
+        public static LoggerConfiguration UmbracoFile(
+            this LoggerSinkConfiguration configuration,
             string path,
             ITextFormatter? formatter = null,
             LogEventLevel restrictedToMinimumLevel = LogEventLevel.Verbose,
@@ -122,30 +165,29 @@ namespace Umbraco.Extensions
             Encoding? encoding = null
    )
         {
+            formatter ??= new CompactJsonFormatter();
 
-            if (formatter is null)
-            {
-                formatter = new CompactJsonFormatter();
-            }
-
+            /* Async sink has an event buffer of 10k events (by default) so we're not constantly thrashing the disk.
+             * I noticed that with File buffered + large number of log entries (global minimum Debug)
+             * an ungraceful shutdown would consistently result in output that just stops halfway through an entry.
+             * with buffered false on the inner sink ungraceful shutdowns still don't seem to wreck the file.
+             */
             return configuration.Async(
-                asyncConfiguration => asyncConfiguration.Map(AppDomainId, (_,mapConfiguration) =>
-                        mapConfiguration.File(
-                            formatter,
-                            path,
-                            restrictedToMinimumLevel,
-                            fileSizeLimitBytes,
-                            levelSwitch,
-                            buffered:true,
-                            shared:false,
-                            flushToDiskInterval,
-                            rollingInterval,
-                            rollOnFileSizeLimit,
-                            retainedFileCountLimit,
-                            encoding,
-                            null),
-                    sinkMapCountLimit:0)
-                );
+                cfg =>
+                    cfg.File(
+                        formatter,
+                        path,
+                        restrictedToMinimumLevel,
+                        fileSizeLimitBytes,
+                        levelSwitch,
+                        buffered: false, // see notes above.
+                        shared: false,
+                        flushToDiskInterval,
+                        rollingInterval,
+                        rollOnFileSizeLimit,
+                        retainedFileCountLimit,
+                        encoding,
+                        null));
         }
 
 
@@ -158,7 +200,7 @@ namespace Umbraco.Extensions
         /// <param name="retainedFileCount">The number of days to keep log files. Default is set to null which means all logs are kept</param>
         public static LoggerConfiguration OutputDefaultJsonFile(
             this LoggerConfiguration logConfig,
-            IHostingEnvironment hostingEnvironment,
+            Umbraco.Cms.Core.Hosting.IHostingEnvironment hostingEnvironment,
             ILoggingConfiguration loggingConfiguration, LogEventLevel minimumLevel = LogEventLevel.Verbose, int? retainedFileCount = null)
         {
             // .clef format (Compact log event format, that can be imported into local SEQ & will make searching/filtering logs easier)
diff --git a/src/Umbraco.Infrastructure/Logging/Serilog/SerilogLogger.cs b/src/Umbraco.Infrastructure/Logging/Serilog/SerilogLogger.cs
index 151f3e760c..2ca43efd0c 100644
--- a/src/Umbraco.Infrastructure/Logging/Serilog/SerilogLogger.cs
+++ b/src/Umbraco.Infrastructure/Logging/Serilog/SerilogLogger.cs
@@ -1,8 +1,8 @@
 using System;
 using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Hosting;
 using Serilog;
 using Serilog.Events;
-using Umbraco.Cms.Core.Hosting;
 using Umbraco.Cms.Infrastructure.Logging.Serilog;
 using Umbraco.Extensions;
 
@@ -21,8 +21,9 @@ namespace Umbraco.Cms.Core.Logging.Serilog
             SerilogLog = logConfig.CreateLogger();
         }
 
+        [Obsolete]
         public static SerilogLogger CreateWithDefaultConfiguration(
-            IHostingEnvironment hostingEnvironment,
+            Umbraco.Cms.Core.Hosting.IHostingEnvironment hostingEnvironment,
             ILoggingConfiguration loggingConfiguration,
             IConfiguration configuration)
         {
@@ -33,8 +34,9 @@ namespace Umbraco.Cms.Core.Logging.Serilog
         /// Creates a logger with some pre-defined configuration and remainder from config file
         /// </summary>
         /// <remarks>Used by UmbracoApplicationBase to get its logger.</remarks>
+        [Obsolete]
         public static SerilogLogger CreateWithDefaultConfiguration(
-            IHostingEnvironment hostingEnvironment,
+            Umbraco.Cms.Core.Hosting.IHostingEnvironment hostingEnvironment,
             ILoggingConfiguration loggingConfiguration,
             IConfiguration configuration,
             out UmbracoFileConfiguration umbracoFileConfig)
diff --git a/src/Umbraco.Infrastructure/Runtime/CoreRuntime.cs b/src/Umbraco.Infrastructure/Runtime/CoreRuntime.cs
index 8889cddebc..ad1622a27e 100644
--- a/src/Umbraco.Infrastructure/Runtime/CoreRuntime.cs
+++ b/src/Umbraco.Infrastructure/Runtime/CoreRuntime.cs
@@ -1,5 +1,6 @@
 using System;
 using System.ComponentModel;
+using System.Diagnostics;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Extensions.DependencyInjection;
@@ -34,8 +35,8 @@ namespace Umbraco.Cms.Infrastructure.Runtime
         private readonly IEventAggregator _eventAggregator;
         private readonly IHostingEnvironment _hostingEnvironment;
         private readonly IUmbracoVersion _umbracoVersion;
-        private readonly IServiceProvider? _serviceProvider;
-        private readonly IHostApplicationLifetime? _hostApplicationLifetime;
+        private readonly IServiceProvider _serviceProvider;
+        private readonly IHostApplicationLifetime _hostApplicationLifetime;
         private readonly ILogger<CoreRuntime> _logger;
         private CancellationToken _cancellationToken;
 
@@ -53,8 +54,8 @@ namespace Umbraco.Cms.Infrastructure.Runtime
             IEventAggregator eventAggregator,
             IHostingEnvironment hostingEnvironment,
             IUmbracoVersion umbracoVersion,
-            IServiceProvider? serviceProvider,
-            IHostApplicationLifetime? hostApplicationLifetime)
+            IServiceProvider serviceProvider,
+            IHostApplicationLifetime hostApplicationLifetime)
         {
             State = state;
 
@@ -85,7 +86,7 @@ namespace Umbraco.Cms.Infrastructure.Runtime
             IEventAggregator eventAggregator,
             IHostingEnvironment hostingEnvironment,
             IUmbracoVersion umbracoVersion,
-            IServiceProvider? serviceProvider)
+            IServiceProvider serviceProvider)
             : this(
                 state,
                 loggerFactory,
@@ -153,14 +154,14 @@ namespace Umbraco.Cms.Infrastructure.Runtime
             // Store token, so we can re-use this during restart
             _cancellationToken = cancellationToken;
 
+            // Just in-case HostBuilder.ConfigureUmbracoDefaults() isn't used (e.g. upgrade from 9 and ignored advice).
+            if (StaticServiceProvider.Instance == null!)
+            {
+                StaticServiceProvider.Instance = _serviceProvider;
+            }
+
             if (isRestarting == false)
             {
-                StaticApplicationLogging.Initialize(_loggerFactory);
-                if (_serviceProvider is not null)
-                {
-                    StaticServiceProvider.Instance = _serviceProvider;
-                }
-
                 AppDomain.CurrentDomain.UnhandledException += (_, args)
                     => _logger.LogError(args.ExceptionObject as Exception, $"Unhandled exception in AppDomain{(args.IsTerminating ? " (terminating)" : null)}.");
             }
@@ -220,8 +221,8 @@ namespace Umbraco.Cms.Infrastructure.Runtime
             if (isRestarting == false)
             {
                 // Add application started and stopped notifications last (to ensure they're always published after starting)
-                _hostApplicationLifetime?.ApplicationStarted.Register(() => _eventAggregator.Publish(new UmbracoApplicationStartedNotification(false)));
-                _hostApplicationLifetime?.ApplicationStopped.Register(() => _eventAggregator.Publish(new UmbracoApplicationStoppedNotification(false)));
+                _hostApplicationLifetime.ApplicationStarted.Register(() => _eventAggregator.Publish(new UmbracoApplicationStartedNotification(false)));
+                _hostApplicationLifetime.ApplicationStopped.Register(() => _eventAggregator.Publish(new UmbracoApplicationStoppedNotification(false)));
             }
         }
 
@@ -233,7 +234,7 @@ namespace Umbraco.Cms.Infrastructure.Runtime
 
         private void AcquireMainDom()
         {
-            using DisposableTimer? timer = _profilingLogger.DebugDuration<CoreRuntime>("Acquiring MainDom.", "Acquired.");
+            using DisposableTimer timer = _profilingLogger.DebugDuration<CoreRuntime>("Acquiring MainDom.", "Acquired.");
 
             try
             {
@@ -254,7 +255,7 @@ namespace Umbraco.Cms.Infrastructure.Runtime
                 return;
             }
 
-            using DisposableTimer? timer = _profilingLogger.DebugDuration<CoreRuntime>("Determining runtime level.", "Determined.");
+            using DisposableTimer timer = _profilingLogger.DebugDuration<CoreRuntime>("Determining runtime level.", "Determined.");
 
             try
             {
diff --git a/src/Umbraco.Web.Common/AspNetCore/AspNetCoreHostingEnvironment.cs b/src/Umbraco.Web.Common/AspNetCore/AspNetCoreHostingEnvironment.cs
index d672f2ae1c..f73fb1b0ae 100644
--- a/src/Umbraco.Web.Common/AspNetCore/AspNetCoreHostingEnvironment.cs
+++ b/src/Umbraco.Web.Common/AspNetCore/AspNetCoreHostingEnvironment.cs
@@ -1,14 +1,15 @@
 using System;
-using System.Collections.Generic;
 using System.IO;
-using System.Threading;
-using Microsoft.AspNetCore.DataProtection;
+using Microsoft.AspNetCore.DataProtection.Infrastructure;
 using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Options;
 using Umbraco.Cms.Core.Collections;
 using Umbraco.Cms.Core.Configuration;
 using Umbraco.Cms.Core.Configuration.Models;
+using Umbraco.Cms.Core.Extensions;
 using Umbraco.Cms.Core.Models.PublishedContent;
+using Umbraco.Cms.Web.Common.Extensions;
 using Umbraco.Extensions;
 using IHostingEnvironment = Umbraco.Cms.Core.Hosting.IHostingEnvironment;
 
@@ -17,21 +18,39 @@ namespace Umbraco.Cms.Web.Common.AspNetCore
     public class AspNetCoreHostingEnvironment : IHostingEnvironment
     {
         private readonly ConcurrentHashSet<Uri> _applicationUrls = new ConcurrentHashSet<Uri>();
-        private readonly IServiceProvider _serviceProvider;
         private readonly IOptionsMonitor<HostingSettings> _hostingSettings;
         private readonly IOptionsMonitor<WebRoutingSettings> _webRoutingSettings;
         private readonly IWebHostEnvironment _webHostEnvironment;
+        private readonly IApplicationDiscriminator? _applicationDiscriminator;
+
         private string? _applicationId;
         private string? _localTempPath;
+
         private UrlMode _urlProviderMode;
 
+        [Obsolete("Please use an alternative constructor.")]
         public AspNetCoreHostingEnvironment(
             IServiceProvider serviceProvider,
             IOptionsMonitor<HostingSettings> hostingSettings,
             IOptionsMonitor<WebRoutingSettings> webRoutingSettings,
             IWebHostEnvironment webHostEnvironment)
+        : this(hostingSettings, webRoutingSettings, webHostEnvironment, serviceProvider.GetService<IApplicationDiscriminator>())
+        {
+        }
+
+        public AspNetCoreHostingEnvironment(
+            IOptionsMonitor<HostingSettings> hostingSettings,
+            IOptionsMonitor<WebRoutingSettings> webRoutingSettings,
+            IWebHostEnvironment webHostEnvironment,
+            IApplicationDiscriminator applicationDiscriminator)
+            : this(hostingSettings, webRoutingSettings, webHostEnvironment) =>
+            _applicationDiscriminator = applicationDiscriminator;
+
+        public AspNetCoreHostingEnvironment(
+            IOptionsMonitor<HostingSettings> hostingSettings,
+            IOptionsMonitor<WebRoutingSettings> webRoutingSettings,
+            IWebHostEnvironment webHostEnvironment)
         {
-            _serviceProvider = serviceProvider;
             _hostingSettings = hostingSettings ?? throw new ArgumentNullException(nameof(hostingSettings));
             _webRoutingSettings = webRoutingSettings ?? throw new ArgumentNullException(nameof(webRoutingSettings));
             _webHostEnvironment = webHostEnvironment ?? throw new ArgumentNullException(nameof(webHostEnvironment));
@@ -74,16 +93,7 @@ namespace Umbraco.Cms.Web.Common.AspNetCore
                     return _applicationId;
                 }
 
-                var appId = _serviceProvider.GetApplicationUniqueIdentifier();
-                if (appId == null)
-                {
-                    throw new InvalidOperationException("Could not acquire an ApplicationId, ensure DataProtection services and an IHostEnvironment are registered");
-                }
-
-                // Hash this value because it can really be anything. By default this will be the application's path.
-                // TODO: Test on IIS, hopefully this would be equivalent to the IIS unique ID.
-                // This could also contain sensitive information (i.e. like the physical path) which we don't want to expose in logs.
-                _applicationId = appId.GenerateHash();
+                _applicationId =  _applicationDiscriminator?.GetApplicationId() ?? _webHostEnvironment.GetTemporaryApplicationId();
 
                 return _applicationId;
             }
@@ -136,27 +146,10 @@ namespace Umbraco.Cms.Web.Common.AspNetCore
         }
 
         /// <inheritdoc/>
-        public string MapPathWebRoot(string path) => MapPath(_webHostEnvironment.WebRootPath, path);
+        public string MapPathWebRoot(string path) => _webHostEnvironment.MapPathWebRoot(path);
 
         /// <inheritdoc/>
-        public string MapPathContentRoot(string path) => MapPath(_webHostEnvironment.ContentRootPath, path);
-
-        private string MapPath(string root, string path)
-        {
-            var newPath = path.Replace('/', Path.DirectorySeparatorChar).Replace('\\', Path.DirectorySeparatorChar);
-
-            // TODO: This is a temporary error because we switched from IOHelper.MapPath to HostingEnvironment.MapPathXXX
-            // IOHelper would check if the path passed in started with the root, and not prepend the root again if it did,
-            // however if you are requesting a path be mapped, it should always assume the path is relative to the root, not
-            // absolute in the file system.  This error will help us find and fix improper uses, and should be removed once
-            // all those uses have been found and fixed
-            if (newPath.StartsWith(root))
-            {
-                throw new ArgumentException("The path appears to already be fully qualified.  Please remove the call to MapPath");
-            }
-
-            return Path.Combine(root, newPath.TrimStart(Core.Constants.CharArrays.TildeForwardSlashBackSlash));
-        }
+        public string MapPathContentRoot(string path) => _webHostEnvironment.MapPathContentRoot(path);
 
         /// <inheritdoc/>
         public string ToAbsolute(string virtualPath)
diff --git a/src/Umbraco.Web.Common/DependencyInjection/UmbracoBuilder.ImageSharp.cs b/src/Umbraco.Web.Common/DependencyInjection/UmbracoBuilder.ImageSharp.cs
index 83144a7466..acf3e903b9 100644
--- a/src/Umbraco.Web.Common/DependencyInjection/UmbracoBuilder.ImageSharp.cs
+++ b/src/Umbraco.Web.Common/DependencyInjection/UmbracoBuilder.ImageSharp.cs
@@ -1,8 +1,8 @@
-using System.Collections.Generic;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Options;
 using Microsoft.Net.Http.Headers;
 using SixLabors.ImageSharp.Web.Caching;
@@ -12,6 +12,7 @@ using SixLabors.ImageSharp.Web.Middleware;
 using SixLabors.ImageSharp.Web.Processors;
 using Umbraco.Cms.Core.Configuration.Models;
 using Umbraco.Cms.Core.DependencyInjection;
+using Umbraco.Cms.Core.Extensions;
 using Umbraco.Cms.Web.Common.DependencyInjection;
 using Umbraco.Cms.Web.Common.ImageProcessors;
 
@@ -73,9 +74,13 @@ namespace Umbraco.Extensions
 
                     return Task.CompletedTask;
                 };
-            })
-                .Configure<PhysicalFileSystemCacheOptions>(options => options.CacheFolder = builder.BuilderHostingEnvironment?.MapPathContentRoot(imagingSettings.Cache.CacheFolder))
-                .AddProcessor<CropWebProcessor>();
+            }).AddProcessor<CropWebProcessor>();
+
+            builder.Services.AddOptions<PhysicalFileSystemCacheOptions>()
+                .Configure<IHostEnvironment>((opt, hostEnvironment) =>
+                {
+                    opt.CacheFolder = hostEnvironment.MapPathContentRoot(imagingSettings.Cache.CacheFolder);
+                });
 
             // Configure middleware to use the registered/shared ImageSharp configuration
             builder.Services.AddTransient<IConfigureOptions<ImageSharpMiddlewareOptions>, ImageSharpConfigurationOptions>();
diff --git a/src/Umbraco.Web.Common/DependencyInjection/UmbracoBuilderExtensions.cs b/src/Umbraco.Web.Common/DependencyInjection/UmbracoBuilderExtensions.cs
index c583ead527..4bc2a49525 100644
--- a/src/Umbraco.Web.Common/DependencyInjection/UmbracoBuilderExtensions.cs
+++ b/src/Umbraco.Web.Common/DependencyInjection/UmbracoBuilderExtensions.cs
@@ -1,23 +1,23 @@
 using System;
 using System.Data.Common;
-using System.IO;
 using System.Linq;
 using System.Net.Http;
 using System.Reflection;
 using Dazinator.Extensions.FileProviders.GlobPatternFilter;
 using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.DataProtection.Infrastructure;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc.ApplicationModels;
 using Microsoft.AspNetCore.Mvc.Razor.Compilation;
 using Microsoft.AspNetCore.Server.Kestrel.Core;
-using Microsoft.Data.SqlClient;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
-using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Logging;
 using Serilog;
+using Serilog.Extensions.Hosting;
+using Serilog.Extensions.Logging;
 using Smidge;
 using Smidge.Cache;
 using Smidge.FileProcessors;
@@ -29,6 +29,7 @@ using Umbraco.Cms.Core.Composing;
 using Umbraco.Cms.Core.Configuration.Models;
 using Umbraco.Cms.Core.DependencyInjection;
 using Umbraco.Cms.Core.Diagnostics;
+using Umbraco.Cms.Core.Extensions;
 using Umbraco.Cms.Core.Hosting;
 using Umbraco.Cms.Core.Logging;
 using Umbraco.Cms.Core.Macros;
@@ -90,15 +91,12 @@ namespace Umbraco.Extensions
                 throw new ArgumentNullException(nameof(config));
             }
 
-            IHostingEnvironment tempHostingEnvironment = GetTemporaryHostingEnvironment(webHostEnvironment, config);
-
-            var loggingDir = tempHostingEnvironment.MapPathContentRoot(Constants.SystemDirectories.LogFiles);
-            var loggingConfig = new LoggingConfiguration(loggingDir);
-
-            services.AddLogger(tempHostingEnvironment, loggingConfig, config);
+            // Setup static application logging ASAP (e.g. during configure services).
+            // Will log to SilentLogger until Serilog.Log.Logger is setup.
+            StaticApplicationLogging.Initialize(new SerilogLoggerFactory());
 
             // The DataDirectory is used to resolve database file paths (directly supported by SQL CE and manually replaced for LocalDB)
-            AppDomain.CurrentDomain.SetData("DataDirectory", tempHostingEnvironment?.MapPathContentRoot(Constants.SystemDirectories.Data));
+            AppDomain.CurrentDomain.SetData("DataDirectory", webHostEnvironment?.MapPathContentRoot(Constants.SystemDirectories.Data));
 
             // Manually create and register the HttpContextAccessor. In theory this should not be registered
             // again by the user but if that is the case it's not the end of the world since HttpContextAccessor
@@ -114,19 +112,17 @@ namespace Umbraco.Extensions
 
             IProfiler profiler = GetWebProfiler(config);
 
-            ILoggerFactory loggerFactory = LoggerFactory.Create(cfg => cfg.AddSerilog(Log.Logger, false));
+            services.AddLogger(webHostEnvironment, config);
 
-            TypeLoader typeLoader = services.AddTypeLoader(
-                Assembly.GetEntryAssembly(),
-                tempHostingEnvironment,
-                loggerFactory,
-                appCaches,
-                config,
-                profiler);
+            ILoggerFactory loggerFactory = new SerilogLoggerFactory();
 
+            TypeLoader typeLoader = services.AddTypeLoader(Assembly.GetEntryAssembly(), loggerFactory, config);
+
+            IHostingEnvironment tempHostingEnvironment = GetTemporaryHostingEnvironment(webHostEnvironment, config);
             return new UmbracoBuilder(services, config, typeLoader, loggerFactory, profiler, appCaches, tempHostingEnvironment);
         }
 
+
         /// <summary>
         /// Adds core Umbraco services
         /// </summary>
@@ -142,7 +138,8 @@ namespace Umbraco.Extensions
 
             // Add ASP.NET specific services
             builder.Services.AddUnique<IBackOfficeInfo, AspNetCoreBackOfficeInfo>();
-            builder.Services.AddUnique<IHostingEnvironment, AspNetCoreHostingEnvironment>();
+            builder.Services.AddUnique<IHostingEnvironment>(sp => ActivatorUtilities.CreateInstance<AspNetCoreHostingEnvironment>(sp, sp.GetRequiredService<IApplicationDiscriminator>()));
+
             builder.Services.AddHostedService(factory => factory.GetRequiredService<IRuntime>());
 
             builder.Services.AddSingleton<DatabaseSchemaCreatorFactory>();
@@ -413,22 +410,15 @@ namespace Umbraco.Extensions
         private static IHostingEnvironment GetTemporaryHostingEnvironment(IWebHostEnvironment webHostEnvironment, IConfiguration config)
         {
             var hostingSettings = config.GetSection(Cms.Core.Constants.Configuration.ConfigHosting).Get<HostingSettings>() ?? new HostingSettings();
-            var webRoutingSettings = config.GetSection(Cms.Core.Constants.Configuration.ConfigWebRouting).Get<WebRoutingSettings>() ?? new WebRoutingSettings();
             var wrappedHostingSettings = new OptionsMonitorAdapter<HostingSettings>(hostingSettings);
+
+            var webRoutingSettings = config.GetSection(Cms.Core.Constants.Configuration.ConfigWebRouting).Get<WebRoutingSettings>() ?? new WebRoutingSettings();
             var wrappedWebRoutingSettings = new OptionsMonitorAdapter<WebRoutingSettings>(webRoutingSettings);
 
-            // This is needed in order to create a unique Application Id
-            var serviceCollection = new ServiceCollection();
-            serviceCollection.AddDataProtection();
-            serviceCollection.AddSingleton<IHostEnvironment>(s => webHostEnvironment);
-            var serviceProvider = serviceCollection.BuildServiceProvider();
-
             return new AspNetCoreHostingEnvironment(
-                serviceProvider,
                 wrappedHostingSettings,
                 wrappedWebRoutingSettings,
                 webHostEnvironment);
         }
-
     }
 }
diff --git a/src/Umbraco.Web.Common/Extensions/ApplicationDiscriminatorExtensions.cs b/src/Umbraco.Web.Common/Extensions/ApplicationDiscriminatorExtensions.cs
new file mode 100644
index 0000000000..398cb40980
--- /dev/null
+++ b/src/Umbraco.Web.Common/Extensions/ApplicationDiscriminatorExtensions.cs
@@ -0,0 +1,35 @@
+using System;
+using Microsoft.AspNetCore.DataProtection.Infrastructure;
+using Umbraco.Extensions;
+
+namespace Umbraco.Cms.Web.Common.Extensions
+{
+    /// <summary>
+    /// Contains extension methods for the <see cref="IApplicationDiscriminator" /> interface.
+    /// </summary>
+    public static class ApplicationDiscriminatorExtensions
+    {
+        private static string s_applicationId;
+
+        /// <summary>
+        /// Gets an application id which respects downstream customizations.
+        /// </summary>
+        /// <remarks>
+        /// Hashed to obscure any unintended infrastructure details e.g. the default value is ContentRootPath.
+        /// </remarks>
+        public static string GetApplicationId(this IApplicationDiscriminator applicationDiscriminator)
+        {
+            if (s_applicationId != null)
+            {
+                return s_applicationId;
+            }
+
+            if (applicationDiscriminator == null)
+            {
+                throw new ArgumentNullException(nameof(applicationDiscriminator));
+            }
+
+            return s_applicationId = applicationDiscriminator.Discriminator.GenerateHash();
+        }
+    }
+}
diff --git a/src/Umbraco.Web.Common/Extensions/ServiceCollectionExtensions.cs b/src/Umbraco.Web.Common/Extensions/ServiceCollectionExtensions.cs
index b8de39bb65..f5a57161d4 100644
--- a/src/Umbraco.Web.Common/Extensions/ServiceCollectionExtensions.cs
+++ b/src/Umbraco.Web.Common/Extensions/ServiceCollectionExtensions.cs
@@ -1,20 +1,28 @@
 using System;
-using System.IO;
 using System.Reflection;
-using Microsoft.AspNetCore.Hosting;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
+using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 using Serilog;
 using Serilog.Extensions.Hosting;
+using Serilog.Extensions.Logging;
 using Umbraco.Cms.Core.Cache;
 using Umbraco.Cms.Core.Composing;
 using Umbraco.Cms.Core.Configuration.Models;
+using Umbraco.Cms.Core.DependencyInjection;
+using Umbraco.Cms.Core.Extensions;
 using Umbraco.Cms.Core.Logging;
 using Umbraco.Cms.Core.Logging.Serilog;
+using Umbraco.Cms.Web.Common.Hosting;
+using Umbraco.Cms.Infrastructure.Logging.Serilog;
+using Umbraco.Cms.Web.Common.Logging.Enrichers;
+using Umbraco.Cms.Core;
+using Umbraco.Cms.Web.Common.Logging;
 using IHostingEnvironment = Umbraco.Cms.Core.Hosting.IHostingEnvironment;
+using ILogger = Serilog.ILogger;
 
 namespace Umbraco.Extensions
 {
@@ -23,6 +31,7 @@ namespace Umbraco.Extensions
         /// <summary>
         /// Create and configure the logger
         /// </summary>
+        [Obsolete("Use the extension method that takes an IHostEnvironment instance instead.")]
         public static IServiceCollection AddLogger(
             this IServiceCollection services,
             IHostingEnvironment hostingEnvironment,
@@ -63,17 +72,103 @@ namespace Umbraco.Extensions
             return services;
         }
 
+        /// <summary>
+        /// Create and configure the logger.
+        /// </summary>
+        /// <remarks>
+        /// Additional Serilog services are registered during <see cref="HostBuilderExtensions.ConfigureUmbracoDefaults"/>.
+        /// </remarks>
+        public static IServiceCollection AddLogger(
+            this IServiceCollection services,
+            IHostEnvironment hostEnvironment,
+            IConfiguration configuration)
+        {
+            // TODO: WEBSITE_RUN_FROM_PACKAGE - can't assume this DIR is writable - we have an IConfiguration instance so a later refactor should be easy enough.
+            var loggingDir = hostEnvironment.MapPathContentRoot(Constants.SystemDirectories.LogFiles);
+            ILoggingConfiguration loggingConfig = new LoggingConfiguration(loggingDir);
+
+            var umbracoFileConfiguration = new UmbracoFileConfiguration(configuration);
+
+            services.TryAddSingleton(umbracoFileConfiguration);
+            services.TryAddSingleton(loggingConfig);
+            services.TryAddSingleton<Serilog.Core.ILogEventEnricher, ApplicationIdEnricher>();
+
+            ///////////////////////////////////////////////
+            // Bootstrap logger setup
+            ///////////////////////////////////////////////
+
+            LoggerConfiguration serilogConfig = new LoggerConfiguration()
+                .MinimalConfiguration(hostEnvironment, loggingConfig, umbracoFileConfiguration)
+                .ReadFrom.Configuration(configuration);
+
+            Log.Logger = serilogConfig.CreateBootstrapLogger();
+
+            ///////////////////////////////////////////////
+            // Runtime logger setup
+            ///////////////////////////////////////////////
+
+            services.AddSingleton(sp =>
+            {
+                var logger = new RegisteredReloadableLogger(Log.Logger as ReloadableLogger);
+
+                logger.Reload(cfg =>
+                {
+                    cfg.MinimalConfiguration(hostEnvironment, loggingConfig, umbracoFileConfiguration)
+                        .ReadFrom.Configuration(configuration)
+                        .ReadFrom.Services(sp);
+
+                    return cfg;
+                });
+
+                return logger;
+            });
+
+            services.AddSingleton<Serilog.ILogger>(sp =>
+            {
+                ILogger logger = sp.GetRequiredService<RegisteredReloadableLogger>().Logger;
+                return logger.ForContext(new NoopEnricher());
+            });
+
+            services.AddSingleton<ILoggerFactory>(sp =>
+            {
+                ILogger logger = sp.GetRequiredService<RegisteredReloadableLogger>().Logger;
+                return new SerilogLoggerFactory(logger, false);
+            });
+
+            // Registered to provide two services...
+            var diagnosticContext = new DiagnosticContext(Log.Logger);
+
+            // Consumed by e.g. middleware
+            services.TryAddSingleton(diagnosticContext);
+
+            // Consumed by user code
+            services.TryAddSingleton<IDiagnosticContext>(diagnosticContext);
+
+            return services;
+        }
+
+        /// <summary>
+        /// Called to create the <see cref="TypeLoader"/> to assign to the <see cref="IUmbracoBuilder"/>
+        /// </summary>
+        /// <remarks>
+        /// This should never be called in a web project. It is used internally by Umbraco but could be used in unit tests.
+        /// If called in a web project it will have no affect except to create and return a new TypeLoader but this will not
+        /// be the instance in DI.
+        /// </remarks>
+        [Obsolete("Please use alternative extension method.")]
+        public static TypeLoader AddTypeLoader(
+            this IServiceCollection services,
+            Assembly entryAssembly,
+            IHostingEnvironment hostingEnvironment,
+            ILoggerFactory loggerFactory,
+            AppCaches appCaches,
+            IConfiguration configuration,
+            IProfiler profiler) =>
+            services.AddTypeLoader(entryAssembly, loggerFactory, configuration);
+
         /// <summary>
         /// Called to create the <see cref="TypeLoader"/> to assign to the <see cref="IUmbracoBuilder"/>
         /// </summary>
-        /// <param name="services"></param>
-        /// <param name="entryAssembly"></param>
-        /// <param name="hostingEnvironment"></param>
-        /// <param name="loggerFactory"></param>
-        /// <param name="appCaches"></param>
-        /// <param name="configuration"></param>
-        /// <param name="profiler"></param>
-        /// <returns></returns>
         /// <remarks>
         /// This should never be called in a web project. It is used internally by Umbraco but could be used in unit tests.
         /// If called in a web project it will have no affect except to create and return a new TypeLoader but this will not
@@ -81,12 +176,9 @@ namespace Umbraco.Extensions
         /// </remarks>
         public static TypeLoader AddTypeLoader(
             this IServiceCollection services,
-            Assembly? entryAssembly,
-            IHostingEnvironment? hostingEnvironment,
+            Assembly entryAssembly,
             ILoggerFactory loggerFactory,
-            AppCaches appCaches,
-            IConfiguration configuration,
-            IProfiler profiler)
+            IConfiguration configuration)
         {
             TypeFinderSettings typeFinderSettings = configuration.GetSection(Cms.Core.Constants.Configuration.ConfigTypeFinder).Get<TypeFinderSettings>() ?? new TypeFinderSettings();
 
@@ -95,30 +187,14 @@ namespace Umbraco.Extensions
                 loggerFactory,
                 typeFinderSettings.AdditionalEntryAssemblies);
 
-            RuntimeHashPaths runtimeHashPaths = new RuntimeHashPaths().AddAssemblies(assemblyProvider);
-
-            var runtimeHash = new RuntimeHash(
-                new ProfilingLogger(
-                    loggerFactory.CreateLogger<RuntimeHash>(),
-                    profiler),
-                runtimeHashPaths);
-
             var typeFinderConfig = new TypeFinderConfig(Options.Create(typeFinderSettings));
 
             var typeFinder = new TypeFinder(
                 loggerFactory.CreateLogger<TypeFinder>(),
                 assemblyProvider,
-                typeFinderConfig
-            );
+                typeFinderConfig);
 
-            var typeLoader = new TypeLoader(
-                typeFinder,
-                runtimeHash,
-                appCaches.RuntimeCache,
-                new DirectoryInfo(hostingEnvironment?.LocalTempPath ?? string.Empty),
-                loggerFactory.CreateLogger<TypeLoader>(),
-                profiler
-            );
+            var typeLoader = new TypeLoader(typeFinder, loggerFactory.CreateLogger<TypeLoader>());
 
             // This will add it ONCE and not again which is what we want since we don't actually want people to call this method
             // in the web project.
diff --git a/src/Umbraco.Web.Common/Extensions/WebHostEnvironmentExtensions.cs b/src/Umbraco.Web.Common/Extensions/WebHostEnvironmentExtensions.cs
new file mode 100644
index 0000000000..78587db1fe
--- /dev/null
+++ b/src/Umbraco.Web.Common/Extensions/WebHostEnvironmentExtensions.cs
@@ -0,0 +1,38 @@
+using System;
+using System.IO;
+using Microsoft.AspNetCore.Hosting;
+
+namespace Umbraco.Cms.Web.Common.Extensions
+{
+    /// <summary>
+    /// Contains extension methods for the <see cref="IWebHostEnvironment" /> interface.
+    /// </summary>
+    public static class WebHostEnvironmentExtensions
+    {
+        /// <summary>
+        /// Maps a virtual path to a physical path to the application's web root
+        /// </summary>
+        /// <remarks>
+        /// Depending on the runtime 'web root', this result can vary. For example in Net Framework the web root and the content root are the same, however
+        /// in netcore the web root is /wwwroot therefore this will Map to a physical path within wwwroot.
+        /// </remarks>
+        public static string MapPathWebRoot(this IWebHostEnvironment webHostEnvironment, string path)
+        {
+            var root = webHostEnvironment.WebRootPath;
+
+            var newPath = path.Replace('/', Path.DirectorySeparatorChar).Replace('\\', Path.DirectorySeparatorChar);
+
+            // TODO: This is a temporary error because we switched from IOHelper.MapPath to HostingEnvironment.MapPathXXX
+            // IOHelper would check if the path passed in started with the root, and not prepend the root again if it did,
+            // however if you are requesting a path be mapped, it should always assume the path is relative to the root, not
+            // absolute in the file system.  This error will help us find and fix improper uses, and should be removed once
+            // all those uses have been found and fixed
+            if (newPath.StartsWith(root))
+            {
+                throw new ArgumentException("The path appears to already be fully qualified.  Please remove the call to MapPathWebRoot");
+            }
+
+            return Path.Combine(root, newPath.TrimStart(Core.Constants.CharArrays.TildeForwardSlashBackSlash));
+        }
+    }
+}
diff --git a/src/Umbraco.Web.Common/Hosting/HostBuilderExtensions.cs b/src/Umbraco.Web.Common/Hosting/HostBuilderExtensions.cs
new file mode 100644
index 0000000000..59f5bac85a
--- /dev/null
+++ b/src/Umbraco.Web.Common/Hosting/HostBuilderExtensions.cs
@@ -0,0 +1,34 @@
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+using Umbraco.Cms.Web.Common.DependencyInjection;
+
+namespace Umbraco.Cms.Web.Common.Hosting;
+
+/// <summary>
+/// Umbraco specific extensions for the <see cref="IHostBuilder"/> interface.
+/// </summary>
+public static class HostBuilderExtensions
+{
+    /// <summary>
+    /// Configures an existing <see cref="IHostBuilder"/> with defaults for an Umbraco application.
+    /// </summary>
+    public static IHostBuilder ConfigureUmbracoDefaults(this IHostBuilder builder)
+    {
+#if DEBUG
+        builder.ConfigureAppConfiguration(config
+            => config.AddJsonFile(
+                "appsettings.Local.json",
+                optional: true,
+                reloadOnChange: true));
+
+#endif
+        builder.ConfigureLogging(x => x.ClearProviders());
+
+        return new UmbracoHostBuilderDecorator(builder, OnHostBuilt);
+    }
+
+    // Runs before any IHostedService starts (including generic web host).
+    private static void OnHostBuilt(IHost host) =>
+        StaticServiceProvider.Instance = host.Services;
+}
diff --git a/src/Umbraco.Web.Common/Hosting/UmbracoHostBuilderDecorator.cs b/src/Umbraco.Web.Common/Hosting/UmbracoHostBuilderDecorator.cs
new file mode 100644
index 0000000000..b2f6fc112c
--- /dev/null
+++ b/src/Umbraco.Web.Common/Hosting/UmbracoHostBuilderDecorator.cs
@@ -0,0 +1,48 @@
+using System;
+using System.Collections.Generic;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+
+namespace Umbraco.Cms.Web.Common.Hosting;
+
+internal class UmbracoHostBuilderDecorator : IHostBuilder
+{
+    private readonly IHostBuilder _inner;
+    private readonly Action<IHost> _onBuild;
+
+    public UmbracoHostBuilderDecorator(IHostBuilder inner, Action<IHost> onBuild = null)
+    {
+        _inner = inner;
+        _onBuild = onBuild;
+    }
+
+    public IHostBuilder ConfigureAppConfiguration(Action<HostBuilderContext, IConfigurationBuilder> configureDelegate) =>
+        _inner.ConfigureAppConfiguration(configureDelegate);
+
+    public IHostBuilder ConfigureContainer<TContainerBuilder>(Action<HostBuilderContext, TContainerBuilder> configureDelegate) =>
+        _inner.ConfigureContainer(configureDelegate);
+
+    public IHostBuilder ConfigureHostConfiguration(Action<IConfigurationBuilder> configureDelegate) =>
+        _inner.ConfigureHostConfiguration(configureDelegate);
+
+    public IHostBuilder ConfigureServices(Action<HostBuilderContext, IServiceCollection> configureDelegate) =>
+        _inner.ConfigureServices(configureDelegate);
+
+    public IHostBuilder UseServiceProviderFactory<TContainerBuilder>(IServiceProviderFactory<TContainerBuilder> factory) =>
+        _inner.UseServiceProviderFactory(factory);
+
+    public IHostBuilder UseServiceProviderFactory<TContainerBuilder>(Func<HostBuilderContext, IServiceProviderFactory<TContainerBuilder>> factory) =>
+        _inner.UseServiceProviderFactory(factory);
+
+    public IDictionary<object, object> Properties => _inner.Properties;
+
+    public IHost Build()
+    {
+        IHost host = _inner.Build();
+
+        _onBuild?.Invoke(host);
+
+        return host;
+    }
+}
diff --git a/src/Umbraco.Web.Common/Logging/Enrichers/ApplicationIdEnricher.cs b/src/Umbraco.Web.Common/Logging/Enrichers/ApplicationIdEnricher.cs
new file mode 100644
index 0000000000..b314745fae
--- /dev/null
+++ b/src/Umbraco.Web.Common/Logging/Enrichers/ApplicationIdEnricher.cs
@@ -0,0 +1,18 @@
+using Microsoft.AspNetCore.DataProtection.Infrastructure;
+using Serilog.Core;
+using Serilog.Events;
+using Umbraco.Cms.Web.Common.Extensions;
+
+namespace Umbraco.Cms.Web.Common.Logging.Enrichers;
+
+internal class ApplicationIdEnricher : ILogEventEnricher
+{
+    private readonly IApplicationDiscriminator _applicationDiscriminator;
+    public const string ApplicationIdProperty = "ApplicationId";
+
+    public ApplicationIdEnricher(IApplicationDiscriminator applicationDiscriminator) =>
+        _applicationDiscriminator = applicationDiscriminator;
+
+    public void Enrich(LogEvent logEvent, ILogEventPropertyFactory propertyFactory) =>
+        logEvent.AddOrUpdateProperty(propertyFactory.CreateProperty(ApplicationIdProperty, _applicationDiscriminator.GetApplicationId()));
+}
diff --git a/src/Umbraco.Web.Common/Logging/Enrichers/NoopEnricher.cs b/src/Umbraco.Web.Common/Logging/Enrichers/NoopEnricher.cs
new file mode 100644
index 0000000000..86402afd45
--- /dev/null
+++ b/src/Umbraco.Web.Common/Logging/Enrichers/NoopEnricher.cs
@@ -0,0 +1,14 @@
+using Serilog.Core;
+using Serilog.Events;
+
+namespace Umbraco.Cms.Web.Common.Logging.Enrichers;
+
+/// <summary>
+/// NoOp but useful for tricks to avoid disposal of the global logger.
+/// </summary>
+internal class NoopEnricher : ILogEventEnricher
+{
+    public void Enrich(LogEvent logEvent, ILogEventPropertyFactory propertyFactory)
+    {
+    }
+}
diff --git a/src/Umbraco.Web.Common/Logging/RegisteredReloadableLogger.cs b/src/Umbraco.Web.Common/Logging/RegisteredReloadableLogger.cs
new file mode 100644
index 0000000000..4bc8ac1dbc
--- /dev/null
+++ b/src/Umbraco.Web.Common/Logging/RegisteredReloadableLogger.cs
@@ -0,0 +1,40 @@
+using System;
+using Serilog;
+using Serilog.Extensions.Hosting;
+
+namespace Umbraco.Cms.Web.Common.Logging;
+
+/// <remarks>
+/// HACK:
+/// Ensures freeze is only called a single time even when resolving a logger from the snapshot container
+/// built for <see cref="ModelsBuilder.RefreshingRazorViewEngine"/>.
+/// </remarks>
+internal class RegisteredReloadableLogger
+{
+    private static bool s_frozen;
+    private static object s_frozenLock = new();
+    private readonly ReloadableLogger _logger;
+
+    public RegisteredReloadableLogger(ReloadableLogger logger) =>
+        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+
+    public ILogger Logger => _logger;
+
+    public void Reload(Func<LoggerConfiguration, LoggerConfiguration> cfg)
+    {
+        lock (s_frozenLock)
+        {
+            if (s_frozen)
+            {
+                Logger.Debug("ReloadableLogger has already been frozen, unable to reload, NOOP.");
+                return;
+            }
+
+            _logger.Reload(cfg);
+            _logger.Freeze();
+
+            s_frozen = true;
+        }
+    }
+}
+
diff --git a/src/Umbraco.Web.UI/Program.cs b/src/Umbraco.Web.UI/Program.cs
index 9b77c126b7..ee0a4774be 100644
--- a/src/Umbraco.Web.UI/Program.cs
+++ b/src/Umbraco.Web.UI/Program.cs
@@ -1,7 +1,6 @@
 using Microsoft.AspNetCore.Hosting;
-using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.Hosting;
-using Microsoft.Extensions.Logging;
+using Umbraco.Cms.Web.Common.Hosting;
 
 namespace Umbraco.Cms.Web.UI
 {
@@ -12,12 +11,9 @@ namespace Umbraco.Cms.Web.UI
                 .Build()
                 .Run();
 
-        public static IHostBuilder CreateHostBuilder(string[] args)
-            => Host.CreateDefaultBuilder(args)
-#if DEBUG
-                .ConfigureAppConfiguration(config => config.AddJsonFile("appsettings.Local.json", optional: true, reloadOnChange: true))
-#endif
-                .ConfigureLogging(x => x.ClearProviders())
+        public static IHostBuilder CreateHostBuilder(string[] args) =>
+            Host.CreateDefaultBuilder(args)
+                .ConfigureUmbracoDefaults()
                 .ConfigureWebHostDefaults(webBuilder => webBuilder.UseStartup<Startup>());
     }
 }
diff --git a/tests/Umbraco.Tests.Benchmarks/TypeLoaderBenchmarks.cs b/tests/Umbraco.Tests.Benchmarks/TypeLoaderBenchmarks.cs
index d11bd6920d..5c3e1ade75 100644
--- a/tests/Umbraco.Tests.Benchmarks/TypeLoaderBenchmarks.cs
+++ b/tests/Umbraco.Tests.Benchmarks/TypeLoaderBenchmarks.cs
@@ -23,28 +23,8 @@ namespace Umbraco.Tests.Benchmarks
                 new NullLogger<TypeFinder>(),
                 new DefaultUmbracoAssemblyProvider(GetType().Assembly, NullLoggerFactory.Instance));
 
-            var cache = new ObjectCacheAppCache();
-            _typeLoader1 = new TypeLoader(
-                typeFinder1,
-                new VaryingRuntimeHash(),
-                cache,
-                null,
-                new NullLogger<TypeLoader>(),
-                new NoopProfiler());
-
-            // populate the cache
-            cache.Insert(
-                _typeLoader1.CacheKey,
-                GetCache,
-                TimeSpan.FromDays(1));
-
-            _typeLoader2 = new TypeLoader(
-                typeFinder1,
-                new VaryingRuntimeHash(),
-                NoAppCache.Instance,
-                null,
-                new NullLogger<TypeLoader>(),
-                new NoopProfiler());
+            _typeLoader1 = new TypeLoader(typeFinder1, NullLogger<TypeLoader>.Instance);
+            _typeLoader2 = new TypeLoader(typeFinder1, NullLogger<TypeLoader>.Instance);
         }
 
         /// <summary>
diff --git a/tests/Umbraco.Tests.Common/Testing/TestHostingEnvironment.cs b/tests/Umbraco.Tests.Common/Testing/TestHostingEnvironment.cs
index e34161a3c2..bd88d80bc0 100644
--- a/tests/Umbraco.Tests.Common/Testing/TestHostingEnvironment.cs
+++ b/tests/Umbraco.Tests.Common/Testing/TestHostingEnvironment.cs
@@ -15,7 +15,7 @@ namespace Umbraco.Cms.Tests.Common.Testing
             IOptionsMonitor<HostingSettings> hostingSettings,
             IOptionsMonitor<WebRoutingSettings> webRoutingSettings,
             IWebHostEnvironment webHostEnvironment)
-            : base(null, hostingSettings, webRoutingSettings, webHostEnvironment)
+            : base(hostingSettings, webRoutingSettings, webHostEnvironment)
         {
         }
 
diff --git a/tests/Umbraco.Tests.Integration/TestServerTest/UmbracoTestServerTestBase.cs b/tests/Umbraco.Tests.Integration/TestServerTest/UmbracoTestServerTestBase.cs
index e25438b03b..f1f8b124e8 100644
--- a/tests/Umbraco.Tests.Integration/TestServerTest/UmbracoTestServerTestBase.cs
+++ b/tests/Umbraco.Tests.Integration/TestServerTest/UmbracoTestServerTestBase.cs
@@ -26,6 +26,7 @@ using Umbraco.Cms.Tests.Integration.DependencyInjection;
 using Umbraco.Cms.Tests.Integration.Testing;
 using Umbraco.Cms.Web.BackOffice.Controllers;
 using Umbraco.Cms.Web.Common.Controllers;
+using Umbraco.Cms.Web.Common.Hosting;
 using Umbraco.Cms.Web.Website.Controllers;
 using Umbraco.Extensions;
 
@@ -136,6 +137,7 @@ namespace Umbraco.Cms.Tests.Integration.TestServerTest
         private IHostBuilder CreateHostBuilder()
         {
             IHostBuilder hostBuilder = Host.CreateDefaultBuilder()
+                .ConfigureUmbracoDefaults()
                 .ConfigureAppConfiguration((context, configBuilder) =>
                 {
                     context.HostingEnvironment = TestHelper.GetWebHostEnvironment();
@@ -197,6 +199,8 @@ namespace Umbraco.Cms.Tests.Integration.TestServerTest
                 Configuration,
                 TestHelper.Profiler);
 
+            services.AddLogger(TestHelper.GetWebHostEnvironment(), Configuration);
+
             var builder = new UmbracoBuilder(services, Configuration, typeLoader, TestHelper.ConsoleLoggerFactory, TestHelper.Profiler, AppCaches.NoCache, hostingEnvironment);
 
             builder
diff --git a/tests/Umbraco.Tests.Integration/Testing/UmbracoIntegrationTest.cs b/tests/Umbraco.Tests.Integration/Testing/UmbracoIntegrationTest.cs
index b11b7ea074..32a58dd702 100644
--- a/tests/Umbraco.Tests.Integration/Testing/UmbracoIntegrationTest.cs
+++ b/tests/Umbraco.Tests.Integration/Testing/UmbracoIntegrationTest.cs
@@ -25,6 +25,7 @@ using Umbraco.Cms.Persistence.SqlServer;
 using Umbraco.Cms.Tests.Common.Builders;
 using Umbraco.Cms.Tests.Integration.DependencyInjection;
 using Umbraco.Cms.Tests.Integration.Extensions;
+using Umbraco.Cms.Web.Common.Hosting;
 using Umbraco.Extensions;
 
 namespace Umbraco.Cms.Tests.Integration.Testing
@@ -66,6 +67,7 @@ namespace Umbraco.Cms.Tests.Integration.Testing
         private IHostBuilder CreateHostBuilder()
         {
             IHostBuilder hostBuilder = Host.CreateDefaultBuilder()
+                .ConfigureUmbracoDefaults()
 
                 // IMPORTANT: We Cannot use UseStartup, there's all sorts of threads about this with testing. Although this can work
                 // if you want to setup your tests this way, it is a bit annoying to do that as the WebApplicationFactory will
@@ -106,6 +108,8 @@ namespace Umbraco.Cms.Tests.Integration.Testing
             // We register this service because we need it for IRuntimeState, if we don't this breaks 900 tests
             services.AddSingleton<IConflictingRouteService, TestConflictingRouteService>();
 
+            services.AddLogger(webHostEnvironment, Configuration);
+
             // Add it!
             Core.Hosting.IHostingEnvironment hostingEnvironment = TestHelper.GetHostingEnvironment();
             TypeLoader typeLoader = services.AddTypeLoader(
@@ -117,8 +121,6 @@ namespace Umbraco.Cms.Tests.Integration.Testing
                 TestHelper.Profiler);
             var builder = new UmbracoBuilder(services, Configuration, typeLoader, TestHelper.ConsoleLoggerFactory, TestHelper.Profiler, AppCaches.NoCache, hostingEnvironment);
 
-            builder.Services.AddLogger(hostingEnvironment, TestHelper.GetLoggingConfiguration(), Configuration);
-
             builder.AddConfiguration()
                 .AddUmbracoCore()
                 .AddWebComponents()
diff --git a/tests/Umbraco.Tests.UnitTests/Umbraco.Core/Composing/TypeLoaderTests.cs b/tests/Umbraco.Tests.UnitTests/Umbraco.Core/Composing/TypeLoaderTests.cs
index c71d89856e..19f04ac869 100644
--- a/tests/Umbraco.Tests.UnitTests/Umbraco.Core/Composing/TypeLoaderTests.cs
+++ b/tests/Umbraco.Tests.UnitTests/Umbraco.Core/Composing/TypeLoaderTests.cs
@@ -115,118 +115,6 @@ namespace Umbraco.Cms.Tests.UnitTests.Umbraco.Core.Composing
         ////    Debug.WriteLine("TOTAL TIME (2nd round): " + watch.ElapsedMilliseconds);
         ////}
 
-        //////NOTE: This test shows that Type.GetType is 100% faster than Assembly.Load(..).GetType(...) so we'll use that :)
-        ////[Test]
-        ////public void Load_Type_Benchmark()
-        ////{
-        ////    var watch = new Stopwatch();
-        ////    watch.Start();
-        ////    for (var i = 0; i < 1000; i++)
-        ////    {
-        ////        var type2 = Type.GetType("umbraco.macroCacheRefresh, umbraco, Version=1.0.4698.259, Culture=neutral, PublicKeyToken=null");
-        ////        var type3 = Type.GetType("umbraco.templateCacheRefresh, umbraco, Version=1.0.4698.259, Culture=neutral, PublicKeyToken=null");
-        ////        var type4 = Type.GetType("umbraco.presentation.cache.MediaLibraryRefreshers, umbraco, Version=1.0.4698.259, Culture=neutral, PublicKeyToken=null");
-        ////        var type5 = Type.GetType("umbraco.presentation.cache.pageRefresher, umbraco, Version=1.0.4698.259, Culture=neutral, PublicKeyToken=null");
-        ////    }
-        ////    watch.Stop();
-        ////    Debug.WriteLine("TOTAL TIME (1st round): " + watch.ElapsedMilliseconds);
-        ////    watch.Reset();
-        ////    watch.Start();
-        ////    for (var i = 0; i < 1000; i++)
-        ////    {
-        ////        var type2 = Assembly.Load("umbraco, Version=1.0.4698.259, Culture=neutral, PublicKeyToken=null")
-        ////            .GetType("umbraco.macroCacheRefresh");
-        ////        var type3 = Assembly.Load("umbraco, Version=1.0.4698.259, Culture=neutral, PublicKeyToken=null")
-        ////            .GetType("umbraco.templateCacheRefresh");
-        ////        var type4 = Assembly.Load("umbraco, Version=1.0.4698.259, Culture=neutral, PublicKeyToken=null")
-        ////            .GetType("umbraco.presentation.cache.MediaLibraryRefreshers");
-        ////        var type5 = Assembly.Load("umbraco, Version=1.0.4698.259, Culture=neutral, PublicKeyToken=null")
-        ////            .GetType("umbraco.presentation.cache.pageRefresher");
-        ////    }
-        ////    watch.Stop();
-        ////    Debug.WriteLine("TOTAL TIME (2nd round): " + watch.ElapsedMilliseconds);
-        ////    watch.Reset();
-        ////    watch.Start();
-        ////    for (var i = 0; i < 1000; i++)
-        ////    {
-        ////        var type2 = BuildManager.GetType("umbraco.macroCacheRefresh, umbraco, Version=1.0.4698.259, Culture=neutral, PublicKeyToken=null", true);
-        ////        var type3 = BuildManager.GetType("umbraco.templateCacheRefresh, umbraco, Version=1.0.4698.259, Culture=neutral, PublicKeyToken=null", true);
-        ////        var type4 = BuildManager.GetType("umbraco.presentation.cache.MediaLibraryRefreshers, umbraco, Version=1.0.4698.259, Culture=neutral, PublicKeyToken=null", true);
-        ////        var type5 = BuildManager.GetType("umbraco.presentation.cache.pageRefresher, umbraco, Version=1.0.4698.259, Culture=neutral, PublicKeyToken=null", true);
-        ////    }
-        ////    watch.Stop();
-        ////    Debug.WriteLine("TOTAL TIME (1st round): " + watch.ElapsedMilliseconds);
-        ////}
-
-        [Test]
-        [Retry(5)] // TODO make this test non-flaky.
-        public void Detect_Legacy_Plugin_File_List()
-        {
-            string filePath = _typeLoader.GetTypesListFilePath();
-            string fileDir = Path.GetDirectoryName(filePath);
-            Directory.CreateDirectory(fileDir);
-
-            File.WriteAllText(filePath, @"<?xml version=""1.0"" encoding=""utf-8""?>
-<plugins>
-<baseType type=""umbraco.interfaces.ICacheRefresher"">
-<add type=""umbraco.macroCacheRefresh, umbraco, Version=6.0.0.0, Culture=neutral, PublicKeyToken=null"" />
-</baseType>
-</plugins>");
-
-            Assert.IsEmpty(_typeLoader.ReadCache()); // uber-legacy cannot be read
-
-            File.Delete(filePath);
-
-            File.WriteAllText(filePath, @"<?xml version=""1.0"" encoding=""utf-8""?>
-<plugins>
-<baseType type=""umbraco.interfaces.ICacheRefresher"" resolutionType=""FindAllTypes"">
-<add type=""umbraco.macroCacheRefresh, umbraco, Version=6.0.0.0, Culture=neutral, PublicKeyToken=null"" />
-</baseType>
-</plugins>");
-
-            Assert.IsEmpty(_typeLoader.ReadCache()); // legacy cannot be read
-
-            File.Delete(filePath);
-
-            File.WriteAllText(filePath, @"IContentFinder
-
-MyContentFinder
-AnotherContentFinder
-
-");
-
-            Assert.IsNotNull(_typeLoader.ReadCache()); // works
-        }
-
-        [Retry(5)] // TODO make this test non-flaky.
-        [Test]
-        public void Create_Cached_Plugin_File()
-        {
-            Type[] types = new[] { typeof(TypeLoader), typeof(TypeLoaderTests), typeof(IUmbracoContext) };
-
-            var typeList1 = new TypeLoader.TypeList(typeof(object), null);
-            foreach (Type type in types)
-            {
-                typeList1.Add(type);
-            }
-
-            _typeLoader.AddTypeList(typeList1);
-            _typeLoader.WriteCache();
-
-            Attempt<IEnumerable<string>> plugins = _typeLoader.TryGetCached(typeof(object), null);
-            Attempt<IEnumerable<string>> diffType = _typeLoader.TryGetCached(typeof(object), typeof(ObsoleteAttribute));
-
-            Assert.IsTrue(plugins.Success);
-
-            // This will be false since there is no cache of that type resolution kind
-            Assert.IsFalse(diffType.Success);
-
-            Assert.AreEqual(3, plugins.Result.Count());
-            IEnumerable<string> shouldContain = types.Select(x => x.AssemblyQualifiedName);
-
-            // Ensure they are all found
-            Assert.IsTrue(plugins.Result.ContainsAll(shouldContain));
-        }
 
         [Test]
         public void Get_Plugins_Hash_With_Hash_Generator()