Observability (o11y)

Monitoring tells you when something is broken. Observability tells you why. It’s the holy trinity of system understanding: logs (what happened), metrics (how much), and traces (where it went).

Observability (o11y, because DevOps loves numeronyms) is about instrumenting your systems so that when the inevitable 3 AM page comes, you can actually diagnose the problem without resorting to kubectl exec and grep.

Why it matters: In distributed systems, you can’t predict every failure mode. Observability lets you ask new questions about your system without deploying new code.