Umbraco-CMS/src/Umbraco.Web.Website/Runtime/WebsiteComposer.cs

using Umbraco.Core;
using Umbraco.Core.Composing;
using Umbraco.Extensions;
using Umbraco.Web.Website.Routing;
using Umbraco.Web.Common.Runtime;

namespace Umbraco.Web.Website.Runtime
{
    // web's initial composer composes after core's, and before all core composers
    [ComposeBefore(typeof(ICoreComposer))]
    [ComposeAfter(typeof(AspNetCoreComposer))]
    public class WebsiteComposer : IComposer
    {
        public void Compose(Composition composition)
        {
            composition.Services.AddUnique<NoContentRoutes>();

            composition
                .ComposeWebsiteUmbracoControllers()
                //.SetDefaultRenderMvcController<RenderMvcController>()// default controller for template views
                ;
        }
    }
}