nodejs-backend-patterns

To standardize a Node.js Express backend, separate routes, controllers, use cases, and repositories into distinct layers. This isolates business logic and data access, enforcing a cohesive architecture for maintainability and consistent test coverage.

The best way to standardize error handling in a Node.js backend is using a disciplined AppError approach alongside Zod for validation. This ensures consistent error throwing across use cases and controllers, providing predictable safety and maintainability.

Yes, this Node.js backend architecture requires PostgreSQL with the pg driver for data access and JWT authentication with rotation for security. These dependencies are enforced to maintain unified infrastructure across server components.

To test Node.js Express controllers and use cases with Vitest, you implement tests within the server/tests directory following the standardized backend pattern. This ensures validation, error handling, and business logic isolation are consistently verified across architectural layers.

JavaScript ESM improves Node.js backend standardization by enforcing modern import and export syntax across routes, middleware, and application layers. Using ESM with Express ensures a cohesive module structure aligning controllers, use cases, and repositories.

You should refactor Express routes into use cases and repositories when business logic and data access become complex or duplicated. This architectural pattern isolates domain entities and application logic, improving test coverage and maintainability across the server.