Clean Architecture in .NET: Practical Implementation

Clean Architecture keeps your business logic independent of frameworks and databases. Here’s how I implement it in .NET projects.

The Layers

• Domain: Entities, value objects, domain events
• Application: Use cases, interfaces, DTOs
• Infrastructure: Database, external services
• WebAPI: Controllers, middleware

Project Structure

src/
├── MyApp.Domain/
├── MyApp.Application/
├── MyApp.Infrastructure/
└── MyApp.WebAPI/

Dependency Rule

Dependencies point inward. Domain has no dependencies. Application depends on Domain. Infrastructure depends on Application.

Example

// Application layer defines interface
public interface IOrderRepository
{
    Task<Order> GetByIdAsync(int id);
}

// Infrastructure implements it
public class OrderRepository : IOrderRepository
{
    private readonly AppDbContext _context;
    public async Task<Order> GetByIdAsync(int id) 
        => await _context.Orders.FindAsync(id);
}

References

• The Clean Architecture – Uncle Bob