Briefing
The last page of the observability blackout is the one that nearly stayed silent: critical alerts have been firing in Prometheus, the alert router accepts them, and not one on-call phone has buzzed for over an hour.
Sam happened to be watching the alert list by hand, which is the only reason anyone knows.
The routing file was restructured this afternoon to add a quiet receiver for noisy synthetic test alerts.
Dev suspects the pager integration key expired.
The fix is yours to find: hints, the recovery checks and the debrief unlock inside the incident.