Express Core Knowledge Deep Knowledge : Use with technology: for comprehensive documentation. Basic Setup Route Patterns Middleware Pattern Error Handler Production Readiness Security Configuration Health Checks Structured Logging Monitoring Metrics | Metric | Alert Threshold | |--------|-----------------| | Request latency p99 | 500ms | | Error rate (5xx) | 1% | | Memory usage | 80% | | Event loop lag | 100ms | | Active handles | 1000 | Graceful Shutdown Error Handler (Production) Checklist - [ ] Helmet security headers enabled - [ ] CORS properly configured - [ ] Rate limiting on API endpoi…