Monitoring & Observability - System Health

When to use this skill

• Setting up application monitoring systems
• Implementing structured logging
• Creating metrics and performance dashboards
• Setting up alerts for critical issues
• Implementing distributed tracing
• Monitoring API performance and latency
• Tracking error rates and exceptions
• Building observability into applications
• Setting up log aggregation
• Creating SLO/SLA monitoring
• Implementing health checks
• Building incident detection systems

When to use this skill

• Setting up metrics, alerts, dashboards.
• When working on related tasks or features
• During development that requires this expertise

Use when: Setting up metrics, alerts, dashboards.

Three Pillars

1. Metrics - Time-series data (CPU, memory, requests/sec)
2. Logs - Event records with context
3. Traces - Request flow through system

Example

```typescript import * as Sentry from '@sentry/node'; import { metrics } from './metrics';

app.use((req, res, next) => { const start = Date.now(); res.on('finish', () => { metrics.histogram('request_duration', Date.now() - start, { method: req.method, route: req.route?.path, status: res.statusCode }); }); next(); }); ```

Resources

• Observability Guide
• Grafana
• Sentry