backend-patterns

Structure a scalable Node.js backend using the repository pattern for data access, a service layer for business logic, and middleware for concerns like authentication and error handling. This separation keeps Express routes clean and maintainable.

The best way to separate business logic from API routes is implementing a service layer. This pattern moves domain logic out of Express controllers into independent services, making code easier to test and maintain across your Node.js application.

The repository pattern works by abstracting database operations behind repository interfaces in your Express API. Controllers and services interact with these repositories instead of the database directly, allowing you to swap databases without rewriting business logic.

Yes, you can use these Node.js backend patterns with Next.js API routes. The Skill provides server-side best practices specifically covering architecture, data access strategies, middleware, and caching that apply directly to Next.js API route implementations.

You do not need external libraries beyond a standard Node.js or TypeScript environment and common libraries to implement caching and error handling patterns. The Skill provides the architectural guidance to apply these performance optimizations directly.

Use middleware for authentication in Node.js to centralize cross-cutting concerns across all routes. Applying middleware patterns prevents duplicated authentication logic in individual Express controllers and ensures consistent error handling throughout your backend.