These incidents are a perfect example of how misleading "simple" systems can be.

From the outside, it looks like "just a cache misconfiguration," but in reality, the problem is more insidious because it's distributed across multiple layers: - application logic (authentication limitations) - CDN behavior -> infrastructure - default settings that users rely on (no cache headers because the CDN was disabled)

The hardest part of debugging these cases isn't identifying what happened, but realizing where the model is flawed: everything appears correct locally, the logs don't report any issues, yet users see completely different data.

I've seen similar cases where developers spent hours debugging the application layer before even considering that something upstream was silently changing the behavior.

These are the kind of incidents where the debugging path is anything but linear.