Observability Stack — Prometheus, Grafana, Loki, Mimir
Observability reference: Prometheus for metrics, Loki for logs, Grafana for visualization, Mimir for long-term storage, plus architecture tradeoffs and deployment patterns.
OpenTelemetry — Instrumentation & Collection
OpenTelemetry reference: SDK setup, collector architecture, auto-instrumentation patterns, sampling strategies, and integration with the Grafana LGTM stack.