backend-patterns

name	backend-patterns
description	Backend architecture patterns, API design, database optimization, and server-side best practices for Node.js, Express, and Next.js API routes.
when_to_use	Use when the user is designing or refactoring APIs, service layers, database access, or backend architecture in Node.js or Next.js projects.

Backend Development Patterns

Backend architecture patterns and best practices for scalable server-side applications.

Pattern Categories

API Design

RESTful structure, Repository pattern, Service layer, Middleware pattern. See references/api-patterns.md for implementations.

Database & Caching

Query optimization, N+1 prevention, transactions, Redis cache-aside pattern. See references/database-caching.md for implementations.

Error Handling, Auth & Infrastructure

Centralized error handler, retry with backoff, JWT/RBAC, rate limiting, job queues, structured logging. See references/error-auth-infra.md for implementations.

Quick Decision Guide

Need	Pattern
Data access abstraction	Repository pattern
Business logic isolation	Service layer
Auth/logging/validation	Middleware pattern
Expensive DB queries	Cache-aside (Redis)
N+1 query problem	Batch fetch with Map
Atomic multi-table writes	Database transactions
Unreliable external APIs	Retry with exponential backoff
Abuse prevention	Rate limiter (in-memory or Redis)
Non-blocking operations	Job queue

Remember: Choose patterns that fit your complexity level. Not every project needs every pattern.