Does we need keep Business Logic Layer when we use CQRS + MediatR in net core?

Question

I use n-tier architecture in my net core applications and I want to apply cqrs + mediator patterns. But I have a question that our handlers should call business (service) layer or repository (data access) layer? Do I need to keep BLL or remove it?

Answer 1

No, you don't need to keep the BLL or DAL layer when you move to a CQRS + MediatR based architecture.

I recommend that you look into vertical slices architecture combined with CQRS/MediatR. See these videos:

• Vertical Slice Architecture - Jimmy Bogard
• Restructuring to a Vertical Slice Architecture

Think an important rule is that you should aim for is code that changes together should also be located together.