diff --git a/src/Umbraco.Tests.Integration/RuntimeTests.cs b/src/Umbraco.Tests.Integration/RuntimeTests.cs
index a5239bf05e..9b09f7c562 100644
--- a/src/Umbraco.Tests.Integration/RuntimeTests.cs
+++ b/src/Umbraco.Tests.Integration/RuntimeTests.cs
@@ -12,7 +12,7 @@ using Umbraco.Core.DependencyInjection;
 using Umbraco.Extensions;
 using Umbraco.Tests.Integration.Extensions;
 using Umbraco.Tests.Integration.Implementations;
-using Umbraco.Web.Common.Extensions;
+using Umbraco.Web.Common.DependencyInjection;
 
 namespace Umbraco.Tests.Integration
 {
@@ -37,7 +37,6 @@ namespace Umbraco.Tests.Integration
         /// <summary>
         /// Calling AddUmbracoCore to configure the container and UseUmbracoCore to start the runtime
         /// </summary>
-        /// <returns></returns>
         [Test]
         public async Task UseUmbracoCore()
         {
diff --git a/src/Umbraco.Tests.Integration/TestServerTest/UmbracoBuilderExtensions.cs b/src/Umbraco.Tests.Integration/TestServerTest/UmbracoBuilderExtensions.cs
index cfab1e29c5..796f9a8669 100644
--- a/src/Umbraco.Tests.Integration/TestServerTest/UmbracoBuilderExtensions.cs
+++ b/src/Umbraco.Tests.Integration/TestServerTest/UmbracoBuilderExtensions.cs
@@ -4,7 +4,7 @@ using Umbraco.Core.Cache;
 using Umbraco.Core.DependencyInjection;
 using Umbraco.Core.Runtime;
 using Umbraco.Tests.Integration.Implementations;
-using Umbraco.Web.Common.Extensions;
+using Umbraco.Web.Common.DependencyInjection;
 
 namespace Umbraco.Tests.Integration.TestServerTest
 {
@@ -13,8 +13,6 @@ namespace Umbraco.Tests.Integration.TestServerTest
         /// <summary>
         /// Uses a test version of Umbraco Core with a test IRuntime
         /// </summary>
-        /// <param name="builder"></param>
-        /// <returns></returns>
         public static IUmbracoBuilder AddTestCore(this IUmbracoBuilder builder, TestHelper testHelper)
         {
             builder.AddUmbracoCore();
diff --git a/src/Umbraco.Tests.Integration/TestServerTest/UmbracoTestServerTestBase.cs b/src/Umbraco.Tests.Integration/TestServerTest/UmbracoTestServerTestBase.cs
index d2b7f1664d..416d0f5835 100644
--- a/src/Umbraco.Tests.Integration/TestServerTest/UmbracoTestServerTestBase.cs
+++ b/src/Umbraco.Tests.Integration/TestServerTest/UmbracoTestServerTestBase.cs
@@ -19,8 +19,9 @@ using Umbraco.Tests.Integration.Testing;
 using Umbraco.Tests.Testing;
 using Umbraco.Web;
 using Umbraco.Web.BackOffice.Controllers;
+using Umbraco.Web.BackOffice.DependencyInjection;
 using Umbraco.Web.Common.Controllers;
-using Umbraco.Web.Common.Extensions;
+using Umbraco.Web.Common.DependencyInjection;
 using Umbraco.Web.Website.Controllers;
 
 namespace Umbraco.Tests.Integration.TestServerTest
diff --git a/src/Umbraco.Tests.Integration/Testing/UmbracoIntegrationTest.cs b/src/Umbraco.Tests.Integration/Testing/UmbracoIntegrationTest.cs
index 27ddcc9fd1..3d50e72b9a 100644
--- a/src/Umbraco.Tests.Integration/Testing/UmbracoIntegrationTest.cs
+++ b/src/Umbraco.Tests.Integration/Testing/UmbracoIntegrationTest.cs
@@ -16,7 +16,6 @@ using NUnit.Framework;
 using Serilog;
 using Umbraco.Core;
 using Umbraco.Core.Cache;
-using Umbraco.Core.Composing;
 using Umbraco.Core.Configuration.Models;
 using Umbraco.Core.DependencyInjection;
 using Umbraco.Core.IO;
@@ -31,7 +30,8 @@ using Umbraco.Tests.Integration.Extensions;
 using Umbraco.Tests.Integration.Implementations;
 using Umbraco.Tests.Testing;
 using Umbraco.Web;
-using Umbraco.Web.Common.Extensions;
+using Umbraco.Web.BackOffice.DependencyInjection;
+using Umbraco.Web.Common.DependencyInjection;
 
 namespace Umbraco.Tests.Integration.Testing
 {
@@ -400,7 +400,7 @@ namespace Umbraco.Tests.Integration.Testing
 
         public IConfiguration Configuration { get; protected set; }
 
-        public TestHelper TestHelper = new TestHelper();
+        public TestHelper TestHelper { get; } = new TestHelper();
 
         protected virtual Action<IServiceCollection> CustomTestSetup => services => { };
 
diff --git a/src/Umbraco.Tests.Integration/Umbraco.Web.BackOffice/UmbracoBackOfficeServiceCollectionExtensionsTests.cs b/src/Umbraco.Tests.Integration/Umbraco.Web.BackOffice/UmbracoBackOfficeServiceCollectionExtensionsTests.cs
index d9dee389ee..b942e57e46 100644
--- a/src/Umbraco.Tests.Integration/Umbraco.Web.BackOffice/UmbracoBackOfficeServiceCollectionExtensionsTests.cs
+++ b/src/Umbraco.Tests.Integration/Umbraco.Web.BackOffice/UmbracoBackOfficeServiceCollectionExtensionsTests.cs
@@ -3,8 +3,8 @@ using Microsoft.AspNetCore.Identity;
 using Microsoft.Extensions.DependencyInjection;
 using NUnit.Framework;
 using Umbraco.Core.Security;
-using Umbraco.Extensions;
 using Umbraco.Tests.Integration.Testing;
+using Umbraco.Web.BackOffice.DependencyInjection;
 using Umbraco.Web.Common.Security;
 
 namespace Umbraco.Tests.Integration.Umbraco.Web.BackOffice
diff --git a/src/Umbraco.Web.BackOffice/Extensions/BackOfficeServiceCollectionExtensions.cs b/src/Umbraco.Web.BackOffice/DependencyInjection/ServiceCollectionExtensions.cs
similarity index 98%
rename from src/Umbraco.Web.BackOffice/Extensions/BackOfficeServiceCollectionExtensions.cs
rename to src/Umbraco.Web.BackOffice/DependencyInjection/ServiceCollectionExtensions.cs
index 9ad448a603..518152a543 100644
--- a/src/Umbraco.Web.BackOffice/Extensions/BackOfficeServiceCollectionExtensions.cs
+++ b/src/Umbraco.Web.BackOffice/DependencyInjection/ServiceCollectionExtensions.cs
@@ -5,6 +5,7 @@ using Microsoft.Extensions.DependencyInjection.Extensions;
 using Umbraco.Core;
 using Umbraco.Core.Security;
 using Umbraco.Core.Serialization;
+using Umbraco.Extensions;
 using Umbraco.Net;
 using Umbraco.Web.Actions;
 using Umbraco.Web.BackOffice.Authorization;
@@ -13,15 +14,13 @@ using Umbraco.Web.Common.AspNetCore;
 using Umbraco.Web.Common.Authorization;
 using Umbraco.Web.Common.Security;
 
-namespace Umbraco.Extensions
+namespace Umbraco.Web.BackOffice.DependencyInjection
 {
-    public static class BackOfficeServiceCollectionExtensions
+    public static class ServiceCollectionExtensions
     {
-
         /// <summary>
         /// Adds the services required for using Umbraco back office Identity
         /// </summary>
-        /// <param name="services"></param>
         public static void AddUmbracoBackOfficeIdentity(this IServiceCollection services)
         {
             services.AddDataProtection();
@@ -79,12 +78,10 @@ namespace Umbraco.Extensions
         /// <summary>
         /// Add authorization handlers and policies
         /// </summary>
-        /// <param name="services"></param>
         public static void AddBackOfficeAuthorizationPolicies(this IServiceCollection services, string backOfficeAuthenticationScheme = Constants.Security.BackOfficeAuthenticationType)
         {
             // NOTE: Even though we are registering these handlers globally they will only actually execute their logic for
-            // any auth defining a matching requirement and scheme. 
-
+            // any auth defining a matching requirement and scheme.
             services.AddSingleton<IAuthorizationHandler, BackOfficeHandler>();
             services.AddSingleton<IAuthorizationHandler, TreeHandler>();
             services.AddSingleton<IAuthorizationHandler, SectionHandler>();
@@ -247,7 +244,7 @@ namespace Umbraco.Extensions
                 policy.Requirements.Add(new SectionRequirement(Constants.Applications.Settings));
             });
 
-            //We will not allow the tree to render unless the user has access to any of the sections that the tree gets rendered
+            // We will not allow the tree to render unless the user has access to any of the sections that the tree gets rendered
             // this is not ideal but until we change permissions to be tree based (not section) there's not much else we can do here.
             options.AddPolicy(AuthorizationPolicies.SectionAccessForContentTree, policy =>
             {
diff --git a/src/Umbraco.Web.BackOffice/Extensions/BackOfficeUmbracoBuilderExtensions.cs b/src/Umbraco.Web.BackOffice/DependencyInjection/UmbracoBuilderExtensions.cs
similarity index 72%
rename from src/Umbraco.Web.BackOffice/Extensions/BackOfficeUmbracoBuilderExtensions.cs
rename to src/Umbraco.Web.BackOffice/DependencyInjection/UmbracoBuilderExtensions.cs
index 16afd976db..9c1d64aba8 100644
--- a/src/Umbraco.Web.BackOffice/Extensions/BackOfficeUmbracoBuilderExtensions.cs
+++ b/src/Umbraco.Web.BackOffice/DependencyInjection/UmbracoBuilderExtensions.cs
@@ -1,16 +1,20 @@
 using System;
+using Microsoft.AspNetCore.Authorization;
 using Microsoft.Extensions.DependencyInjection;
 using Umbraco.Core.DependencyInjection;
 using Umbraco.Infrastructure.PublishedCache.Extensions;
+using Umbraco.Web.BackOffice.Authorization;
 using Umbraco.Web.BackOffice.Security;
-using Umbraco.Web.Common.Extensions;
+using Umbraco.Web.BackOffice.Trees;
+using Umbraco.Web.Common.Authorization;
+using Umbraco.Web.Common.DependencyInjection;
 
-namespace Umbraco.Extensions
+namespace Umbraco.Web.BackOffice.DependencyInjection
 {
     /// <summary>
     /// Extension methods for <see cref="IUmbracoBuilder"/> for the Umbraco back office
     /// </summary>
-    public static class BackOfficeUmbracoBuilderExtensions
+    public static partial class UmbracoBuilderExtensions
     {
         /// <summary>
         /// Adds all required components to run the Umbraco back office
@@ -76,14 +80,15 @@ namespace Umbraco.Extensions
         /// <summary>
         /// Adds Umbraco back office authorization policies
         /// </summary>
-        public static IUmbracoBuilder AddBackOfficeAuthorizationPolicies(this IUmbracoBuilder builder, string backOfficeAuthenticationScheme = Umbraco.Core.Constants.Security.BackOfficeAuthenticationType)
+        public static IUmbracoBuilder AddBackOfficeAuthorizationPolicies(this IUmbracoBuilder builder, string backOfficeAuthenticationScheme = Core.Constants.Security.BackOfficeAuthenticationType)
         {
             builder.Services.AddBackOfficeAuthorizationPolicies(backOfficeAuthenticationScheme);
 
-            // TODO: See other TODOs in things like UmbracoApiControllerBase ... AFAIK all of this is only used for the back office
-            // so IMO these controllers and the features auth policies should just be moved to the back office project and then this
-            // ext method can be removed.
-            builder.Services.AddUmbracoCommonAuthorizationPolicies();
+            builder.Services.AddSingleton<IAuthorizationHandler, FeatureAuthorizeHandler>();
+
+            builder.Services.AddAuthorization(options
+                => options.AddPolicy(AuthorizationPolicies.UmbracoFeatureEnabled, policy
+                    => policy.Requirements.Add(new FeatureAuthorizeRequirement())));
 
             return builder;
         }
@@ -97,5 +102,20 @@ namespace Umbraco.Extensions
 
             return builder;
         }
+
+        /// <summary>
+        /// Adds support for external login providers in Umbraco
+        /// </summary>
+        public static IUmbracoBuilder AddBackOfficeExternalLogins(this IUmbracoBuilder umbracoBuilder, Action<BackOfficeExternalLoginsBuilder> builder)
+        {
+            builder(new BackOfficeExternalLoginsBuilder(umbracoBuilder.Services));
+            return umbracoBuilder;
+        }
+
+        /// <summary>
+        /// Gets the back office tree collection builder
+        /// </summary>
+        public static TreeCollectionBuilder Trees(this IUmbracoBuilder builder)
+            => builder.WithCollectionBuilder<TreeCollectionBuilder>();
     }
 }
diff --git a/src/Umbraco.Web.BackOffice/Extensions/AuthenticationBuilderExtensions.cs b/src/Umbraco.Web.BackOffice/Extensions/AuthenticationBuilderExtensions.cs
deleted file mode 100644
index 8145cb4278..0000000000
--- a/src/Umbraco.Web.BackOffice/Extensions/AuthenticationBuilderExtensions.cs
+++ /dev/null
@@ -1,16 +0,0 @@
-using System;
-using Umbraco.Core.DependencyInjection;
-using Umbraco.Web.BackOffice.Security;
-
-namespace Umbraco.Extensions
-{
-    public static class AuthenticationBuilderExtensions
-    {
-        public static IUmbracoBuilder AddBackOfficeExternalLogins(this IUmbracoBuilder umbracoBuilder, Action<BackOfficeExternalLoginsBuilder> builder)
-        {
-            builder(new BackOfficeExternalLoginsBuilder(umbracoBuilder.Services));
-            return umbracoBuilder;
-        }
-    }
-
-}
diff --git a/src/Umbraco.Web.BackOffice/Extensions/CompositionExtensions.cs b/src/Umbraco.Web.BackOffice/Extensions/CompositionExtensions.cs
deleted file mode 100644
index 2c14e33e2b..0000000000
--- a/src/Umbraco.Web.BackOffice/Extensions/CompositionExtensions.cs
+++ /dev/null
@@ -1,29 +0,0 @@
-using Umbraco.Core.DependencyInjection;
-using Umbraco.Core.Composing;
-using Umbraco.Web.BackOffice.Trees;
-
-// the namespace here is intentional -  although defined in Umbraco.Web assembly,
-// this class should be visible when using Umbraco.Core.Components, alongside
-// Umbraco.Core's own CompositionExtensions class
-
-// ReSharper disable once CheckNamespace
-namespace Umbraco.Extensions
-{
-    /// <summary>
-    /// Provides extension methods to the <see cref="Composition"/> class.
-    /// </summary>
-    public static class WebCompositionExtensions
-    {
-        #region Collection Builders
-
-        /// <summary>
-        /// Gets the back office tree collection builder
-        /// </summary>
-        /// <param name="builder"></param>
-        /// <returns></returns>
-        public static TreeCollectionBuilder Trees(this IUmbracoBuilder builder)
-            => builder.WithCollectionBuilder<TreeCollectionBuilder>();
-
-        #endregion
-    }
-}
diff --git a/src/Umbraco.Web.BackOffice/Extensions/IdentityBuilderExtensions.cs b/src/Umbraco.Web.BackOffice/Extensions/IdentityBuilderExtensions.cs
index e6385e6bf9..dcb0606ebb 100644
--- a/src/Umbraco.Web.BackOffice/Extensions/IdentityBuilderExtensions.cs
+++ b/src/Umbraco.Web.BackOffice/Extensions/IdentityBuilderExtensions.cs
@@ -4,15 +4,20 @@ using Umbraco.Core.Security;
 
 namespace Umbraco.Extensions
 {
+    /// <summary>
+    /// Extension methods for <see cref="IdentityBuilder"/>
+    /// </summary>
     public static class IdentityBuilderExtensions
     {
         /// <summary>
         /// Adds a <see cref="UserManager{TUser}"/> implementation for <seealso cref="BackOfficeIdentityUser"/>
         /// </summary>
-        /// <typeparam name="TUserManager">The type of the user manager to add.</typeparam>
-        /// <typeparam name="TInterface"></typeparam>
+        /// <typeparam name="TInterface">The usermanager interface</typeparam>
+        /// <typeparam name="TUserManager">The usermanager type</typeparam>
+        /// <param name="identityBuilder">The <see cref="IdentityBuilder"/></param>
         /// <returns>The current <see cref="IdentityBuilder"/> instance.</returns>
-        public static IdentityBuilder AddUserManager<TInterface, TUserManager>(this IdentityBuilder identityBuilder) where TUserManager : UserManager<BackOfficeIdentityUser>, TInterface
+        public static IdentityBuilder AddUserManager<TInterface, TUserManager>(this IdentityBuilder identityBuilder)
+            where TUserManager : UserManager<BackOfficeIdentityUser>, TInterface
         {
             identityBuilder.AddUserManager<TUserManager>();
             identityBuilder.Services.AddScoped(typeof(TInterface), typeof(TUserManager));
@@ -22,11 +27,12 @@ namespace Umbraco.Extensions
         /// <summary>
         /// Adds a <see cref="SignInManager{TUser}"/> implementation for <seealso cref="BackOfficeIdentityUser"/>
         /// </summary>
-        /// <typeparam name="TInterface"></typeparam>
-        /// <typeparam name="TSignInManager"></typeparam>
-        /// <param name="identityBuilder"></param>
-        /// <returns></returns>
-        public static IdentityBuilder AddSignInManager<TInterface, TSignInManager>(this IdentityBuilder identityBuilder) where TSignInManager : SignInManager<BackOfficeIdentityUser>, TInterface
+        /// <typeparam name="TInterface">The sign in manager interface</typeparam>
+        /// <typeparam name="TSignInManager">The sign in manager type</typeparam>
+        /// <param name="identityBuilder">The <see cref="IdentityBuilder"/></param>
+        /// <returns>The current <see cref="IdentityBuilder"/> instance.</returns>
+        public static IdentityBuilder AddSignInManager<TInterface, TSignInManager>(this IdentityBuilder identityBuilder)
+            where TSignInManager : SignInManager<BackOfficeIdentityUser>, TInterface
         {
             identityBuilder.AddSignInManager<TSignInManager>();
             identityBuilder.Services.AddScoped(typeof(TInterface), typeof(TSignInManager));
diff --git a/src/Umbraco.Web.BackOffice/Runtime/BackOfficeComposer.cs b/src/Umbraco.Web.BackOffice/Runtime/BackOfficeComposer.cs
index 44896016cd..e9bf69f2c0 100644
--- a/src/Umbraco.Web.BackOffice/Runtime/BackOfficeComposer.cs
+++ b/src/Umbraco.Web.BackOffice/Runtime/BackOfficeComposer.cs
@@ -1,14 +1,15 @@
-using System.Linq;
+using System.Linq;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using Umbraco.Core;
-using Umbraco.Core.DependencyInjection;
 using Umbraco.Core.Composing;
+using Umbraco.Core.DependencyInjection;
 using Umbraco.Core.Hosting;
 using Umbraco.Core.IO;
 using Umbraco.Core.Services;
 using Umbraco.Extensions;
 using Umbraco.Web.BackOffice.Controllers;
+using Umbraco.Web.BackOffice.DependencyInjection;
 using Umbraco.Web.BackOffice.Filters;
 using Umbraco.Web.BackOffice.Middleware;
 using Umbraco.Web.BackOffice.Routing;
diff --git a/src/Umbraco.Web.Common/AspNetCore/UmbracoMvcConfigureOptions.cs b/src/Umbraco.Web.Common/AspNetCore/UmbracoMvcConfigureOptions.cs
new file mode 100644
index 0000000000..6c8420cd03
--- /dev/null
+++ b/src/Umbraco.Web.Common/AspNetCore/UmbracoMvcConfigureOptions.cs
@@ -0,0 +1,24 @@
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.Extensions.Options;
+using Umbraco.Web.Common.Filters;
+using Umbraco.Web.Common.ModelBinders;
+
+namespace Umbraco.Web.Common.AspNetCore
+{
+    /// <summary>
+    /// Options for globally configuring MVC for Umbraco
+    /// </summary>
+    /// <remarks>
+    /// We generally don't want to change the global MVC settings since we want to be unobtrusive as possible but some
+    /// global mods are needed - so long as they don't interfere with normal user usages of MVC.
+    /// </remarks>
+    public class UmbracoMvcConfigureOptions : IConfigureOptions<MvcOptions>
+    {
+        /// <inheritdoc/>
+        public void Configure(MvcOptions options)
+        {
+            options.ModelBinderProviders.Insert(0, new ContentModelBinderProvider());
+            options.Filters.Insert(0, new EnsurePartialViewMacroViewContextFilterAttribute());
+        }
+    }
+}
diff --git a/src/Umbraco.Web.Common/Extensions/UmbracoWebServiceCollectionExtensions.cs b/src/Umbraco.Web.Common/DependencyInjection/ServiceCollectionExtensions.cs
similarity index 67%
rename from src/Umbraco.Web.Common/Extensions/UmbracoWebServiceCollectionExtensions.cs
rename to src/Umbraco.Web.Common/DependencyInjection/ServiceCollectionExtensions.cs
index 2b077fe840..dd7eda895e 100644
--- a/src/Umbraco.Web.Common/Extensions/UmbracoWebServiceCollectionExtensions.cs
+++ b/src/Umbraco.Web.Common/DependencyInjection/ServiceCollectionExtensions.cs
@@ -1,37 +1,22 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Mvc;
-using Microsoft.AspNetCore.Mvc.ApplicationModels;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.DependencyInjection.Extensions;
-using Microsoft.Extensions.Options;
 using SixLabors.ImageSharp.Memory;
 using SixLabors.ImageSharp.Web.Caching;
 using SixLabors.ImageSharp.Web.Commands;
 using SixLabors.ImageSharp.Web.DependencyInjection;
 using SixLabors.ImageSharp.Web.Processors;
 using SixLabors.ImageSharp.Web.Providers;
-using Smidge;
-using Smidge.Nuglify;
-using Umbraco.Core.DependencyInjection;
 using Umbraco.Core.Configuration.Models;
-using Umbraco.Core.Configuration.Models.Validation;
-using Umbraco.Web.Common.ApplicationModels;
 
-namespace Umbraco.Extensions
+namespace Umbraco.Web.Common.DependencyInjection
 {
-    public static class UmbracoWebServiceCollectionExtensions
+    public static class ServiceCollectionExtensions
     {
-     
-
-
         /// <summary>
         /// Adds Image Sharp with Umbraco settings
         /// </summary>
-        /// <param name="services"></param>
-        /// <param name="configuration"></param>
-        /// <returns></returns>
         public static IServiceCollection AddUmbracoImageSharp(this IServiceCollection services, IConfiguration configuration)
         {
             var imagingSettings = configuration.GetSection(Core.Constants.Configuration.ConfigImaging)
@@ -50,7 +35,7 @@ namespace Umbraco.Extensions
 
                             return Task.CompletedTask;
                         };
-                        options.OnBeforeSaveAsync = _ =>  Task.CompletedTask;
+                        options.OnBeforeSaveAsync = _ => Task.CompletedTask;
                         options.OnProcessedAsync = _ => Task.CompletedTask;
                         options.OnPrepareResponseAsync = _ => Task.CompletedTask;
                     })
@@ -70,7 +55,6 @@ namespace Umbraco.Extensions
             return services;
         }
 
-
         private static void RemoveIntParamenterIfValueGreatherThen(IDictionary<string, string> commands, string parameter, int maxValue)
         {
             if (commands.TryGetValue(parameter, out var command))
@@ -84,30 +68,5 @@ namespace Umbraco.Extensions
                 }
             }
         }
-
-        /// <summary>
-        /// Options for globally configuring MVC for Umbraco
-        /// </summary>
-        /// <remarks>
-        /// We generally don't want to change the global MVC settings since we want to be unobtrusive as possible but some
-        /// global mods are needed - so long as they don't interfere with normal user usages of MVC.
-        /// </remarks>
-        public class UmbracoMvcConfigureOptions : IConfigureOptions<MvcOptions>
-        {
-
-            // TODO: we can inject params with DI here
-            public UmbracoMvcConfigureOptions()
-            {
-            }
-
-            // TODO: we can configure global mvc options here if we need to
-            public void Configure(MvcOptions options)
-            {
-
-            }
-        }
-
-
     }
-
 }
diff --git a/src/Umbraco.Web.Common/Extensions/UmbracoBuilderExtensions.cs b/src/Umbraco.Web.Common/DependencyInjection/UmbracoBuilderExtensions.cs
similarity index 91%
rename from src/Umbraco.Web.Common/Extensions/UmbracoBuilderExtensions.cs
rename to src/Umbraco.Web.Common/DependencyInjection/UmbracoBuilderExtensions.cs
index 80185f30a3..c524cb064d 100644
--- a/src/Umbraco.Web.Common/Extensions/UmbracoBuilderExtensions.cs
+++ b/src/Umbraco.Web.Common/DependencyInjection/UmbracoBuilderExtensions.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.Data.Common;
 using System.Data.SqlClient;
 using System.IO;
@@ -7,7 +8,6 @@ using System.Runtime.InteropServices;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Http;
-using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.Mvc.ApplicationModels;
 using Microsoft.AspNetCore.Server.Kestrel.Core;
 using Microsoft.Extensions.Configuration;
@@ -36,21 +36,19 @@ using Umbraco.Infrastructure.HostedServices.ServerRegistration;
 using Umbraco.Infrastructure.Runtime;
 using Umbraco.Web.Common.ApplicationModels;
 using Umbraco.Web.Common.AspNetCore;
-using Umbraco.Web.Common.Extensions;
-using Umbraco.Web.Common.Filters;
-using Umbraco.Web.Common.ModelBinders;
+using Umbraco.Web.Common.DependencyInjection;
 using Umbraco.Web.Common.Profiler;
 using Umbraco.Web.Telemetry;
 using IHostingEnvironment = Umbraco.Core.Hosting.IHostingEnvironment;
 
-namespace Umbraco.Web.Common.Extensions
+namespace Umbraco.Web.Common.DependencyInjection
 {
     // TODO: We could add parameters to configure each of these for flexibility
 
     /// <summary>
     /// Extension methods for <see cref="IUmbracoBuilder"/> for the common Umbraco functionality
     /// </summary>
-    public static class UmbracoBuilderExtensions
+    public static partial class UmbracoBuilderExtensions
     {
         public static IUmbracoBuilder AddUmbraco(
             this IServiceCollection services,
@@ -90,11 +88,15 @@ namespace Umbraco.Web.Common.Extensions
             return new UmbracoBuilder(services, config, typeLoader, loggerFactory);
         }
 
-        /// <remarks>Composes Composers</remarks>
+        /// <summary>
+        /// Adds core Umbraco services
+        /// </summary>
         public static IUmbracoBuilder AddUmbracoCore(this IUmbracoBuilder builder)
         {
             if (builder is null)
+            {
                 throw new ArgumentNullException(nameof(builder));
+            }
 
             builder.Services.AddLazySupport();
 
@@ -163,15 +165,21 @@ namespace Umbraco.Web.Common.Extensions
             return builder;
         }
 
+        /// <summary>
+        /// Adds Umbraco composers for plugins
+        /// </summary>
         public static IUmbracoBuilder AddComposers(this IUmbracoBuilder builder)
         {
-            var composerTypes = builder.TypeLoader.GetTypes<IComposer>();
-            var enableDisable = builder.TypeLoader.GetAssemblyAttributes(typeof(EnableComposerAttribute), typeof(DisableComposerAttribute));
+            IEnumerable<Type> composerTypes = builder.TypeLoader.GetTypes<IComposer>();
+            IEnumerable<Attribute> enableDisable = builder.TypeLoader.GetAssemblyAttributes(typeof(EnableComposerAttribute), typeof(DisableComposerAttribute));
             new Composers(builder, composerTypes, enableDisable, builder.BuilderLoggerFactory.CreateLogger<Composers>()).Compose();
 
             return builder;
         }
 
+        /// <summary>
+        /// Add Umbraco configuration services and options
+        /// </summary>
         public static IUmbracoBuilder AddConfiguration(this IUmbracoBuilder builder)
         {
             // Register configuration validators.
@@ -208,6 +216,9 @@ namespace Umbraco.Web.Common.Extensions
             return builder;
         }
 
+        /// <summary>
+        /// Add Umbraco hosted services
+        /// </summary>
         public static IUmbracoBuilder AddHostedServices(this IUmbracoBuilder builder)
         {
             builder.Services.AddHostedService<HealthCheckNotifier>();
@@ -221,40 +232,44 @@ namespace Umbraco.Web.Common.Extensions
             return builder;
         }
 
+        // TODO: Not sure this needs to exist and/or be public?
         public static IUmbracoBuilder AddHttpClients(this IUmbracoBuilder builder)
         {
             builder.Services.AddHttpClient();
             return builder;
         }
 
+        /// <summary>
+        /// Adds mini profiler services for Umbraco
+        /// </summary>
         public static IUmbracoBuilder AddMiniProfiler(this IUmbracoBuilder builder)
         {
             builder.Services.AddMiniProfiler(options =>
-            {
-                options.ShouldProfile = request => false; // WebProfiler determine and start profiling. We should not use the MiniProfilerMiddleware to also profile
-            });
+
+                // WebProfiler determine and start profiling. We should not use the MiniProfilerMiddleware to also profile
+                options.ShouldProfile = request => false);
 
             return builder;
         }
 
-        public static IUmbracoBuilder AddMvcAndRazor(this IUmbracoBuilder builder, Action<MvcOptions> mvcOptions = null, Action<IMvcBuilder> mvcBuilding = null)
+        public static IUmbracoBuilder AddMvcAndRazor(this IUmbracoBuilder builder, Action<IMvcBuilder> mvcBuilding = null)
         {
             // TODO: We need to figure out if we can work around this because calling AddControllersWithViews modifies the global app and order is very important
             // this will directly affect developers who need to call that themselves.
             // We need to have runtime compilation of views when using umbraco. We could consider having only this when a specific config is set.
             // But as far as I can see, there are still precompiled views, even when this is activated, so maybe it is okay.
-            var mvcBuilder = builder.Services.AddControllersWithViews(options =>
-            {
-                options.ModelBinderProviders.Insert(0, new ContentModelBinderProvider());
+            IMvcBuilder mvcBuilder = builder.Services
+                .AddControllersWithViews()
+                .AddRazorRuntimeCompilation();
 
-                options.Filters.Insert(0, new EnsurePartialViewMacroViewContextFilterAttribute());
-                mvcOptions?.Invoke(options);
-            }).AddRazorRuntimeCompilation();
             mvcBuilding?.Invoke(mvcBuilder);
 
             return builder;
         }
 
+        /// <summary>
+        /// Add runtime minifier support for Umbraco
+        /// </summary>
         public static IUmbracoBuilder AddRuntimeMinifier(this IUmbracoBuilder builder)
         {
             builder.Services.AddSmidge(builder.Config.GetSection(Core.Constants.Configuration.ConfigRuntimeMinification));
@@ -274,7 +289,7 @@ namespace Umbraco.Web.Common.Extensions
                 options.Cookie.HttpOnly = true;
             });
 
-            builder.Services.ConfigureOptions<UmbracoWebServiceCollectionExtensions.UmbracoMvcConfigureOptions>();
+            builder.Services.ConfigureOptions<UmbracoMvcConfigureOptions>();
             builder.Services.TryAddEnumerable(ServiceDescriptor.Transient<IApplicationModelProvider, UmbracoApiBehaviorApplicationModelProvider>());
             builder.Services.TryAddEnumerable(ServiceDescriptor.Transient<IApplicationModelProvider, BackOfficeApplicationModelProvider>());
             builder.Services.AddUmbracoImageSharp(builder.Config);
@@ -282,9 +297,10 @@ namespace Umbraco.Web.Common.Extensions
             return builder;
         }
 
+        // TODO: Does this need to exist and/or be public?
         public static IUmbracoBuilder AddWebServer(this IUmbracoBuilder builder)
         {
-            // TODO: We need to figure out why thsi is needed and fix those endpoints to not need them, we don't want to change global things
+            // TODO: We need to figure out why this is needed and fix those endpoints to not need them, we don't want to change global things
             // If using Kestrel: https://stackoverflow.com/a/55196057
             builder.Services.Configure<KestrelServerOptions>(options =>
             {
diff --git a/src/Umbraco.Web.Common/Extensions/ApplicationBuilderExtensions.cs b/src/Umbraco.Web.Common/Extensions/ApplicationBuilderExtensions.cs
index 0f2d1ffcdd..5c7c4ee713 100644
--- a/src/Umbraco.Web.Common/Extensions/ApplicationBuilderExtensions.cs
+++ b/src/Umbraco.Web.Common/Extensions/ApplicationBuilderExtensions.cs
@@ -14,7 +14,6 @@ using Umbraco.Core.Hosting;
 using Umbraco.Infrastructure.Logging.Serilog.Enrichers;
 using Umbraco.Web.Common.Middleware;
 using Umbraco.Web.Common.Plugins;
-using Umbraco.Web.PublishedCache.NuCache;
 
 namespace Umbraco.Extensions
 {
diff --git a/src/Umbraco.Web.Common/Extensions/ServiceCollectionExtensions.cs b/src/Umbraco.Web.Common/Extensions/ServiceCollectionExtensions.cs
deleted file mode 100644
index e8e3e2c329..0000000000
--- a/src/Umbraco.Web.Common/Extensions/ServiceCollectionExtensions.cs
+++ /dev/null
@@ -1,25 +0,0 @@
-using Microsoft.AspNetCore.Authorization;
-using Microsoft.Extensions.DependencyInjection;
-using Umbraco.Web.BackOffice.Authorization;
-using Umbraco.Web.Common.Authorization;
-
-namespace Umbraco.Extensions
-{
-    public static class ServiceCollectionExtensions
-    {
-        public static void AddUmbracoCommonAuthorizationPolicies(this IServiceCollection services)
-        {
-            // TODO: Should this only exist in the back office project? These really are only ever used for the back office AFAIK
-            // If it is moved it should only target the back office scheme
-
-            services.AddSingleton<IAuthorizationHandler, FeatureAuthorizeHandler>();
-
-            services.AddAuthorization(options =>
-            {
-                options.AddPolicy(AuthorizationPolicies.UmbracoFeatureEnabled, policy =>
-                    policy.Requirements.Add(new FeatureAuthorizeRequirement()));
-            });
-        }
-    }
-
-}
diff --git a/src/Umbraco.Web.UI.NetCore/Startup.cs b/src/Umbraco.Web.UI.NetCore/Startup.cs
index d16015101d..eb7c8f5c04 100644
--- a/src/Umbraco.Web.UI.NetCore/Startup.cs
+++ b/src/Umbraco.Web.UI.NetCore/Startup.cs
@@ -4,8 +4,12 @@ using Microsoft.AspNetCore.Hosting;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
-using Umbraco.Core.DependencyInjection;
+using Microsoft.Identity.Web;
 using Umbraco.Extensions;
+using Umbraco.Web.BackOffice.DependencyInjection;
+using Umbraco.Web.BackOffice.Security;
+using Umbraco.Web.Common.DependencyInjection;
+using Umbraco.Web.Website.DependencyInjection;
 
 namespace Umbraco.Web.UI.NetCore
 {
@@ -29,6 +33,7 @@ namespace Umbraco.Web.UI.NetCore
         }
 
 
+
         /// <summary>
         /// Configures the services
         /// </summary>
@@ -40,10 +45,11 @@ namespace Umbraco.Web.UI.NetCore
         {
 #pragma warning disable IDE0022 // Use expression body for methods
             services.AddUmbraco(_env, _config)
-                .AddAllBackOfficeComponents()
-                .AddUmbracoWebsite()
+                .AddBackOffice()
+                .AddWebsite()
                 .Build();
 #pragma warning restore IDE0022 // Use expression body for methods
+
         }
 
         /// <summary>
diff --git a/src/Umbraco.Web.Website/Extensions/UmbracoWebsiteApplicationBuilderExtensions.cs b/src/Umbraco.Web.Website/Extensions/UmbracoWebsiteApplicationBuilderExtensions.cs
index 438ad154ed..5ceb5e523f 100644
--- a/src/Umbraco.Web.Website/Extensions/UmbracoWebsiteApplicationBuilderExtensions.cs
+++ b/src/Umbraco.Web.Website/Extensions/UmbracoWebsiteApplicationBuilderExtensions.cs
@@ -1,7 +1,6 @@
 using System;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.Extensions.DependencyInjection;
-using SixLabors.ImageSharp.Web.DependencyInjection;
 using Umbraco.Web.Website.Routing;
 
 namespace Umbraco.Extensions
diff --git a/src/Umbraco.Web.Website/Extensions/WebsiteUmbracoBuilderExtensions.cs b/src/Umbraco.Web.Website/Extensions/WebsiteUmbracoBuilderExtensions.cs
deleted file mode 100644
index 204f97ae30..0000000000
--- a/src/Umbraco.Web.Website/Extensions/WebsiteUmbracoBuilderExtensions.cs
+++ /dev/null
@@ -1,44 +0,0 @@
-using Microsoft.AspNetCore.Mvc;
-using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.Options;
-using Umbraco.Core.DependencyInjection;
-using Umbraco.Infrastructure.PublishedCache.Extensions;
-using Umbraco.Web.Website.Controllers;
-using Umbraco.Web.Website.Routing;
-using Umbraco.Web.Website.ViewEngines;
-
-namespace Umbraco.Extensions
-{
-    /// <summary>
-    /// <see cref="IUmbracoBuilder"/> extensions for umbraco front-end website
-    /// </summary>
-    public static class WebsiteUmbracoBuilderExtensions
-    {
-        /// <summary>
-        /// Add services for the umbraco front-end website
-        /// </summary>
-        public static IUmbracoBuilder AddWebsite(this IUmbracoBuilder builder)
-        {
-            // Set the render & plugin view engines (Super complicated, but this allows us to use the IServiceCollection
-            // to inject dependencies into the viewEngines)
-            builder.Services.AddTransient<IConfigureOptions<MvcViewOptions>, RenderMvcViewOptionsSetup>();
-            builder.Services.AddSingleton<IRenderViewEngine, RenderViewEngine>();
-            builder.Services.AddTransient<IConfigureOptions<MvcViewOptions>, PluginMvcViewOptionsSetup>();
-            builder.Services.AddSingleton<IPluginViewEngine, PluginViewEngine>();
-
-            // Wraps all existing view engines in a ProfilerViewEngine
-            builder.Services.AddTransient<IConfigureOptions<MvcViewOptions>, ProfilingViewEngineWrapperMvcViewOptionsSetup>();
-
-            // TODO figure out if we need more to work on load balanced setups
-            builder.Services.AddDataProtection();
-
-            builder.Services.AddScoped<UmbracoRouteValueTransformer>();
-            builder.Services.AddSingleton<IUmbracoRenderingDefaults, UmbracoRenderingDefaults>();
-
-            builder.AddNuCache();
-
-            return builder;
-        }
-
-    }
-}