Observability interview prep

APM Platforms — Application Performance Monitoring — integrated traces + metrics + logs + RUM + profiling in one product. Data
Debugging a Broken Alerting Pipeline — Systematic approach to diagnosing why alerts stopped firing during a production incident.
Distributed Tracing — Trace requests across service boundaries. Spans, parent/child relationships, baggage, sampling. Tools: Jaeger
eBPF Observability — Kernel-level observability without code changes. eBPF runs verified programs at kprobes/uprobes/tracepoints/XD
Log Aggregation — Centralized logs across services. Three storage models: full-text indexed (Elasticsearch / OpenSearch), label-
OpenTelemetry — CNCF Incubating project; second-most-active CNCF project after Kubernetes. Vendor-neutral spec for traces, met
OpenTelemetry Collector — Pipelines & Deployment — OTel Collector: receivers, processors, exporters. Tail-based vs head-based sampling. Agent/Gateway topology. K
Prometheus & Grafana — CNCF Graduated metrics stack. Prometheus pulls metrics on intervals, stores TSDB locally. Grafana queries via
SLO / SLI / Error Budgets — Service Level Indicators (what you measure), Service Level Objectives (target you commit to), and Error Budget