backend-patterns

Prevent N+1 queries by applying repository and service layer separation to optimize database indexing and query fetching. This pattern batches related data requests, eliminating redundant loops over database records in Node.js and Next.js APIs.

Structure scalable backend APIs by implementing distinct controller, service, and repository layers. This separation of concerns simplifies testing and maintenance while isolating business logic from data access in Express and Node.js applications.

Add a Redis cache-aside layer by intercepting service layer requests to check cache availability before querying the database. This strategy significantly reduces database load and improves API response times for read-heavy operations.

Implement role-based access control and JWT validation in Next.js API routes using middleware. Middleware intercepts requests to verify tokens and enforce user permissions before passing traffic to the controller layer.

External API retry logic needs exponential backoff to prevent cascading failures during network outages or rate limits. Delaying retries progressively avoids overwhelming the recovering service and ensures transactional safety.