Primitive 09 / Postmortem

Postmortem card

The structured public postmortem we publish after a Sev2-and-above incident. Title, date, author, a numbered 5-Whys list, an action-items block with owners and due-dates, and a lessons-learned panel.

Production answer

Postmortem card is a reusable Oak Flats Muffler Men UI primitive with documented states, accessibility expectations, theme behavior, and implementation evidence.

Primary CTAReview Postmortem card states
Generative search brief

Postmortem card: The structured public postmortem we publish after a Sev2-and-above incident. Title, date, author, a numbered 5-Whys list, an action-items block with owners and due-dates, and a lessons-learned panel.

Live primitive · SMS delivery delay postmortem
Postmortem · 27 May 2026

Customer SMS delivery delays in APAC-1

By Sasha B · SRE

5 Whys

  1. 1Customers in APAC-1 saw 5-minute booking confirmation delays.
  2. 2Because the carrier's primary route returned 5xx at 14:32 UTC.
  3. 3Because the carrier failed over without honouring our route-pinning header.
  4. 4Because the route-pin extension is opt-in and our APAC account wasn't enrolled.
  5. 5Because the enrollment task slipped during the 2025 carrier-consolidation epic.

Action items

  • Add carrier-side failover health-check to alerting before customer-visible threshold.Jess R · Booking · due 2026-06-10
    Open
  • Stand up secondary SMS partner with auto-route at >2% delivery failure for 5 minutes.Marcus P · Parts · due 2026-06-21
    Open
  • Document APAC failover runbook and rehearse in next game-day.Sasha B · SRE · due 2026-07-04
    Open

Lessons learned

We over-trusted the carrier's primary route and treated a multi-region SMS partner as a single dependency. From now on every customer-impacting carrier dependency must have an automated failover test in the on-call game-day.