Every new signup posts a message to our Slack. The format is dull and reliable: Overnight this week one arrived like this: That trailing nothing was the entire incident. No error logs, no alerts. A returning user had signed up, our signup service had attached them to a tenant we deprovisioned back in December, and the only symptom in the whole company was a Slack message that ran out of words. Their company's email domain still pointed at the dead tenant, so instead of a fresh workspace they landed in a corpse: domain mapping still live, cloud infrastructure long gone. I'm on call this week, so I pulled the thread.
