What's the recommended folder structure of catalogs in project using IoC

What I usually do is that I have a MyApplication.Core (Class library) layer, which contains all the applications interfaces with as little (read: none) third-party dependencies, e.g. ILogger, ICommand or IQuery<TResult>.

Next I have a MyApplication.Domain (Class library) layer which contains all the application domain specific knowledge - this is the business layer. This is implementations of the core interfaces ICommand, IQuery<TResult>. These implementations then have an dependency on e.g. ILogger. Never concrete implementations.

Then I have the MyApplication.Infrastructure (Class library) which is where all the service interfaces from MyApplication.Core is implemented, e.g. ILogger. Here you can have dependencies on third-party libraries such as Log4Net.

Then last I have the presentation layer, which is in my case usually an MVC applications so I would name this MyApplication.Web.Mvc. All controllers have only dependencies on the interfaces. Never concrete implementations. This layer is also responsible of bootstrapping all the interfaces to the concrete implementations using a Composition Root.

TL;DR:

  • MyApplication.Core (Application Interface Layer)
  • MyApplication.Domain (Business Logic)
  • MyApplication.Infrastructure (Implementations of Application Interface Layer)
  • MyApplication.Web.Mvc (Presentation and Composition Root Layer)