System Design - 20. Observability: The 3 Pillars, 4 Golden Signals, and How Netflix Debugs 100 Microservices

Covers: Metrics/Logs/Traces, 4 Golden Signals, Distributed Tracing, Alert Fatigue, SLO-Based Alerting The 3am Page With No Answer Imagine you're on-call. At 3am, an alert fires: "API error rate abov