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observability
also logs, metrics, traces
Logs say what happened. Metrics say how often. Traces say which hop was slow.
What is observability?
Observability is being able to ask a new question of a running system without shipping a new log line first. The three tools are structured logs, metrics, and traces. `console.log("here")` is none of them.
Why does observability matter when vibe coding?
Models sprinkle `console.log` and call the app debuggable. In production you cannot attach a debugger to the vibe. Name the three signals or the next outage is a guessing game.
How do you do observability?
One structured log per request with an id. One metric for the user-visible failure. A trace across the handler and the database. No secrets in any of them.
How do you ask a model for observability?
Add observability, not print debugging. Structured log with a request id, one metric for failures, and a trace across handler and database. Do not log secrets or full payloads.
What goes wrong with observability?
Logging every object. That is a bill and a leak, not observability.