Observability

Observability is increasingly asked in SDE-2 and SRE-flavored frontend interviews: you need to explain the three pillars, how monitoring differs from observability, and how to instrument apps with OpenTelemetry.

This module covers Golden Signals, Prometheus and Grafana, distributed tracing, high-cardinality pitfalls, SLIs/SLOs/SLAs, error budgets, and production observability best practices.

Frontend engineers increasingly own client-side reliability: you will learn to instrument React apps, define meaningful SLOs, avoid alert fatigue, and use traces to debug slow API calls across services.

Topics span metrics vs logs vs traces, Golden Signals, Prometheus pull model, Grafana dashboards, OpenTelemetry instrumentation, SLI/SLO/SLA chains, error budgets, and Kubernetes monitoring with ServiceMonitors.

Phase 10 (Weeks 10–12) of the interview roadmap. Senior Track spans modules 1–19; the Staff Track starts at module 20.