nodejs-backend-patterns

Use a layered architecture with separate directories for controllers, services, repositories, models, middleware, and routes. Controllers handle HTTP requests, services contain business logic, and repositories manage data access, wired together through a dependency injection container.

Express is a minimalist framework with a large middleware ecosystem suited for general APIs. Fastify offers higher performance, built-in Pino logging, and type-safe routes with JSON schema validation, making it better for performance-critical services.

Create middleware that extracts the Bearer token from the authorization header, verifies it with jsonwebtoken against your JWT secret, and attaches the decoded payload to the request object. Use short-lived access tokens (15 minutes) with 7-day refresh tokens.

Acquire a client from the pg Pool, run BEGIN, execute your queries, then COMMIT on success or ROLLBACK on error inside a try-catch block. Always release the client in a finally block to return it to the connection pool.

The default in-memory store does not share state between instances. Use express-rate-limit with rate-limit-redis and an ioredis client so all instances enforce limits against a shared Redis store.

Zod provides schema-based validation that parses request body, query, and params before they reach your controller. Validation errors can be mapped to field-level messages and returned as structured 400 responses through a validation middleware.