QA Observability and Performance Engineering

Use telemetry (logs, metrics, traces, profiles) as a QA signal and a debugging substrate.

Core references:

• OpenTelemetry: https://opentelemetry.io/docs/
• W3C Trace Context: https://www.w3.org/TR/trace-context/
• Google SRE SLOs: https://sre.google/sre-book/service-level-objectives/

Default QA stance

• Treat telemetry as part of acceptance criteria (especially for integration/E2E tests).
• Require correlation: request_id + trace_id (traceparent) across boundaries.
• Prefer SLO-based release gating and burn-rate alerting over raw infra thresholds.
• Budget overhead: sampling, cardinality, retention, and cost are quality constraints.
• Redact PII/secrets by default (logs and attributes).

Core workflows

1. Establish the minimum bar (logs + metrics + traces + correlation).
2. Instrument with OpenTelemetry (auto-instrument first, then add manual spans for key paths).
3. Verify context propagation across service boundaries (traceparent in/out).
4. Define SLIs/SLOs and error budget policy; wire burn-rate alerts.
5. Make failures diagnosable: capture a trace link + key logs on every test failure.
6. Profile and load test only after telemetry is reliable; validate against baselines.

Quick reference

| Task | Recommended default | Notes | |------|---------------------|-------| | Tracing | OpenTelemetry + Jaeger/Tempo | Prefer OTLP exporters via Collector when possible | | Metrics | Prometheus + Grafana | Use histograms for latency; watch cardinality | | Logging | Structured JSON + correlation IDs | Never log secrets/PII; redact aggressively | | Reliability gates | SLOs + error budgets + burn-rate alerts | Gate releases on sustained burn/regressions | | Performance | Profiling + load tests + budgets | Add continuous profiling for intermittent issues | | Zero-code visibility | eBPF (OpenTelemetry zero-code) + continuous profiling (Parca/Pyroscope) | Use when code changes are not feasible |

Navigation

Open these guides when needed:

| If the user needs... | Read | Also use | |---|---|---| | A minimal, production-ready baseline | references/core-observability-patterns.md | assets/checklists/template-observability-readiness-checklist.md | | Node/Python instrumentation setup | references/opentelemetry-best-practices.md | assets/opentelemetry/nodejs/opentelemetry-nodejs-setup.md, assets/opentelemetry/python/opentelemetry-python-setup.md | | Working trace propagation across services | references/distributed-tracing-patterns.md | assets/checklists/template-observability-readiness-checklist.md | | SLOs, burn-rate alerts, and release gates | references/slo-design-guide.md | assets/monitoring/slo/slo-definition.yaml, assets/monitoring/slo/prometheus-alert-rules.yaml | | Profiling/load testing with evidence | references/performance-profiling-guide.md | assets/load-testing/load-testing-k6.js, assets/load-testing/template-load-test-artillery.yaml | | A maturity model and roadmap | references/observability-maturity-model.md | assets/checklists/template-observability-readiness-checklist.md | | What to avoid and how to fix it | references/anti-patterns-best-practices.md | assets/checklists/template-observability-readiness-checklist.md |

Implementation guides (deep dives):

• references/core-observability-patterns.md
• references/opentelemetry-best-practices.md
• references/distributed-tracing-patterns.md
• references/slo-design-guide.md
• references/performance-profiling-guide.md
• references/observability-maturity-model.md
• references/anti-patterns-best-practices.md

Templates (copy/paste):

• assets/checklists/template-observability-readiness-checklist.md
• assets/opentelemetry/nodejs/opentelemetry-nodejs-setup.md
• assets/opentelemetry/python/opentelemetry-python-setup.md
• assets/monitoring/slo/slo-definition.yaml
• assets/monitoring/slo/prometheus-alert-rules.yaml
• assets/monitoring/grafana/grafana-dashboard-slo.json
• assets/monitoring/grafana/template-grafana-dashboard-observability.json
• assets/load-testing/load-testing-k6.js
• assets/load-testing/template-load-test-artillery.yaml
• assets/performance/frontend/template-lighthouse-ci.json
• assets/performance/backend/template-nodejs-profiling-config.js

Curated sources:

• data/sources.json

Scope boundaries (handoffs)

• Pure infrastructure monitoring (Kubernetes, Docker, CI/CD): ../ops-devops-platform/SKILL.md
• Database query optimization (SQL tuning, indexing): ../data-sql-optimization/SKILL.md
• Application-level debugging (stack traces, breakpoints): ../qa-debugging/SKILL.md
• Test strategy design (coverage, test pyramids): ../qa-testing-strategy/SKILL.md
• Resilience patterns (retries, circuit breakers): ../qa-resilience/SKILL.md
• Architecture decisions (microservices, event-driven): ../software-architecture-design/SKILL.md

Tool selection notes (2026)

• Default to OpenTelemetry + OTLP + Collector where possible.
• Prefer burn-rate alerting against SLOs over alerting on raw infra metrics.
• Treat sampling, cardinality, and retention as part of quality (not an afterthought).
• When asked to pick vendors/tools, start from data/sources.json and validate time-sensitive claims with current docs/releases if the environment allows it.