Observability Operations
Request Logger Middleware
Async /health Readiness Endpoint
Maintenance-Mode Middleware
Streaming Realtime
Stream File Download Endpoint
Stream Large Result Set as CSV
Streaming Reverse Proxy Route
Range-Aware File Streaming Endpoint
Long-Polling Endpoint With Timeout
Routing Resource Design
Filter Collection With Optional Query Params
Custom 404 JSON Fallback Route
Versioned API Router With express.Router
Header-Based API Versioning Router
RESTful CRUD Resource for Tasks
Preload Resource With router.param
Mount an Admin Sub-Application
Filesystem-Based Route Auto-Registration
Authentication Authorization
Bcrypt Login With JWT Issuance
JWT Authentication Guard Middleware
Role-Based Access Middleware Factory
Session-Based Login and Logout
API-Key Auth With Rate Limiting
Rotating Refresh Token Endpoint
Error Handling Resilience
Centralized Error-Handling Middleware
Async Route Error Wrapper
Request Timeout Middleware With 504
Graceful Shutdown on SIGTERM and SIGINT
Circuit Breaker for Outbound Calls
File Uploads Static Serving
Validated Image Upload With Multer
Serve Static Files, Block .secret
Multer Multi-File Upload Validation
Multi-File Attachment System
Security Hardening
Restrict CORS to One Origin
Manual Security Headers Middleware
HMAC Request Signature Verification Middleware
CSRF Protection Middleware
Signature-Verified Webhook Receiver
Idempotency Middleware for POST Requests
Validation Sanitization
Schema Validation Middleware Factory
Validated POST /register Endpoint
Input Sanitization Middleware
Bulk Create With Per-Item Results
Request Processing Body Parsing
Create User Validation Middleware
Trim Whitespace Sanitizer Middleware
Parse and Set a Signed Cookie
Reject Oversized Bodies With 413
snake_case to camelCase Response Interceptor
Caching Conditional Responses
Gzip Compression Above Size Threshold
Conditional GET With Last-Modified
ETag Caching Middleware With 304
Content Negotiation Rendering
Mount Swagger UI at /docs
Render a Page With a View Engine
Content Negotiation With res.format
Accept-Language i18n Middleware
Data Access Api Patterns
DB Connection Injection Middleware
In-Memory IP Rate Limiter Middleware
Chat Backend With Auth and Messaging
Leads API With CRUD and RBAC
Transactional POST With Rollback
Cursor-Based Pagination for GET /items
Subdomain Tenant Resolver Middleware