Backend Architect Skill

To structure a TypeScript backend with Domain-Driven Design, separate your code into distinct Domain, Application, Infrastructure, and Presentation layers. This approach encapsulates business logic within domain entities and services while using thin Express controllers for API routing.

Using Prisma ORM with PostgreSQL in an Express application involves integrating Prisma within the infrastructure layer for data access. This setup provides efficient data persistence while keeping data mapping isolated from your domain and application services.

The best way to separate business logic from Express controllers is to implement a layered architecture where controllers remain thin. Push business rules into domain entities and application services, ensuring your presentation layer only handles HTTP requests and responses.

Yes, you can build a user authentication microservice with DDD in Node.js by encapsulating validation and error handling within domain entities and application services. This method ensures strict typing and test coverage using TypeScript, Express, and Prisma.

DDD layered architecture improves TypeScript code maintainability by enforcing a clean separation of concerns and strict typing. Isolating domain logic from infrastructure and presentation layers makes the codebase easier to scale and test.

You should not use Domain-Driven Design for a backend API when building simple CRUD applications with minimal business logic. The overhead of maintaining distinct Domain, Application, and Infrastructure layers outweighs the benefits for basic data entry and retrieval tasks.