A Cloud Run + Firebase App Check CORS postmortem Users couldn't log in. No crash. No server...
Cloud Build's deploy flag stripped IAM bindings while App Check middleware blocked preflight OPTIONS, silently locking users out of production. Tech leaders must treat CORS errors as infrastructure issues and audit CI/CD IAM flags plus middleware order.
A Cloud Run + Firebase App Check CORS postmortem
Users couldn't log in.
No crash. No server error. No deployment alarm. Just a wave of CORS failures quietly rolling through production while everything on our end looked completely normal.
This is the story of how two unrelated bugs combined to cause a login outage — and how we found them.
The Symptom
How a Missing CDN Dependency Broke Our Frontend on One Network Introduction A few days after...
The deploy was green. The build passed. And my data just... stopped updating. No crash. No red. No...
1. The Incident I was building Friday OS—my self-hosted, local-first AI Personal OS. The...
At 2:17 AM, your phone buzzes three times. The product group chat explodes with 9 messages: "Login...
One morning, email on our primary domain just... stopped working. No bounce messages. No error a...
We had one of those bugs that looked small from the outside, but exposed a much deeper architecture...
