Multi Layer .Net 6 App

Question

I've been debating with a friend, what'd be the best practices for project layers.

I've chosen:

• UI
• API
• Services
• Dal
• Models

He's chosen:

• UI
• API
• DAL

In his opinion I could have the logic on the API controllers and access DAL directly.
He would also have DTO models inside DAL and cascade down objects to API layer.

So what'd be the best approach ?
I understand that keeping the controller clean just calling the services would be better for organization, and also if I want to plug a desktop application to the solution later, but for something else ?
Also having the Models in a project apart, wouldn't be better ?

Please give me your thoughts.
Thx

Answer 1

neither seems enough layers for an enterprise project.

just for the DAL I'd have at least 3 projects (layers)

DAL-API - dal model and interfaces
DAL-Rules - dal internal rules and logic
DAL-Database - actual database calls

you want to abstract each layer as much as possible, and use adapters for communication between layers.