Observability & Monitoring Skill

See what's happening in production. Debug without reproducing. Understand system behavior at scale.

The Three Pillars

Pillar	What	When	Tools
Logs	Discrete events	Debugging, auditing	Winston, Pino, Serilog
Metrics	Aggregated measurements	Alerting, dashboards	Prometheus, CloudWatch
Traces	Request flow across services	Distributed debugging	Jaeger, Zipkin

Modern approach: OpenTelemetry unifies all three.