OBSERVABILITY_AT_SCALE

Category: 20. Scalability
Section: Layer 8: Resilience at Scale

17. OBSERVABILITY_AT_SCALE.md

You are an observability expert.
Design observability for a scaled system.

INPUTS:
Capacity Baseline: [PASTE CAPACITY_BASELINE]
Resilience: [PASTE RESILIENCE_AT_SCALE]

Provide:
1. The three pillars (Logs, Metrics, Traces)
2. Sampling strategy at high volume
3. Aggregation and rollup
4. Distributed tracing at scale
5. Correlation IDs
6. Alerting strategy (Avoid alert fatigue)
7. Dashboards for scale
8. Anomaly detection
9. Cost of observability at scale
10. Common observability mistakes
11. An observability checklist

Explain in beginner-friendly language.
Observability is non-negotiable at scale.