Observability Instrumentation

Degree of freedom: MIXED. What to wrap and alert on [HIGH freedom]; correlation ids, PII redaction, and the DoD [LOW freedom — run exactly].

How to reason

1. Observe — which ids, logs, spans, and PII already exist
2. Interpret — can you pivot error ↔ trace ↔ log ↔ user from any one?
3. Classify — add-correlation / convert-console / redact / wrap-span / alert
4. Severity — uncorrelated prod 500 outranks a missing debug field

Worked example

Observe: checkout 500 in Sentry has no request_id; pino logs the cart id; no LLM (Langfuse unused). Interpret: cannot pivot error → logs; webhook still console.logs. Classify: ALS request_id on logs + Sentry.setTag; convert console to pino; redact Authorization. Verify: one id on the Sentry event and the log line; beforeSend strips the header.