Backend Development Patterns Backend architecture patterns, API design, database optimization, and server-side best practices for Node.js, Express, and Next.js API routes. API Design Patterns RESTful API Structure Repository Pattern Service Layer Pattern Middleware Pattern Database Patterns Query Optimization N+1 Query Prevention Transaction Pattern Caching Strategies Redis Caching Layer Cache-Aside Pattern Error Handling Patterns Centralized Error Handler Retry with Exponential Backoff Authentication & Authorization JWT Token Validation Role-Based Access Control Rate Limiting Simple In-Memor…