Debugging the Invisible: Why Event Systems Need Their Own Observability Layer
A QA tester files a bug: "The door doesn't open when the player picks up the key."
Simple, right? Probably a missing reference or a wrong condition. You open the project, pick up the key, and... the door opens fine. Works on your machine. So you ask the tester for reproduction steps, and they say "it happens about 30% of the time, usually after a save/load cycle."
Now you're in debugging hell. Somewhere in the chain between the key pickup event, the inventory update, the quest progress check, and the door's unlock condition, something is failing intermittently. But which link? Was the event not raised? Was it raised but the listener wasn't subscribed? Was the listener subscribed but the condition evaluated to false? Was the condition correct but the door's state was stale after the load?