A scraper pipeline I maintain stopped publishing for five weeks. Every morning the report said the same thing: logged in, ready to capture . Nothing was captured.

It was not broken in any dramatic way. It was broken the way most automation breaks: a check answered a question slightly different from the one that mattered, and the answer was always yes.

Here are the three shapes I found, and the probe rules I now apply everywhere.

1. "Logged in" measured the presence of a file

The check ran auth status --offline . That flag does exactly what it says: read the credential file, make no network request. The session behind it had been rejected with a 401 nineteen days earlier. The file was still there, so the verdict was "logged in, you can capture now".

With a cache in front of reality, liveness and existence become different questions.…