logging-observability

Structured logging, distributed tracing, and metrics for production applications. [What: OpenTelemetry setup, log level strategy, correlation IDs, SLI/SLO alerting thresholds, Grafana dashboard design, PagerDuty integration] [When: setting up production logging, adding observability to a service, debugging distributed systems, designing alerting, implementing traces/metrics/logs] [Keywords: logging, observability, OpenTelemetry, OTel, structured logs, distributed tracing, correlation ID, metrics, Grafana, Prometheus, PagerDuty, Winston, Pino, structlog, log levels, SLI, SLO, alerting] NOT for application performance profiling (use a profiler), load testing, or database query optimization.