I was two hours into a bug and completely certain it was mine. Properties I'd added on the Java side of an application weren't showing up on the JavaScript side. I'd just touched that code. It had to be my change — that's not a hunch, that's just how these things go, you break the thing you were last inside of. I spent the better part of an hour re-reading my own diff, convinced the answer was somewhere in it, because it obviously had to be.
It wasn't in my diff. It was a legacy codegen sync script, three steps removed from anything I'd touched, quietly failing to invalidate an old artifact. I didn't find that out by getting smarter. I found it out by walking away from my own certainty, twice, guided by a checklist I'd set long before I ever opened that file.
Here's that checklist, the same one every time. I go through this checklist anytime I'm about to dig into a problem that I know might be tricky.
Before you start — while you're calm, not while you're stuck — decide how long you're willing to work under pressure before you're required to stop. I typically set this at two hours.
Decide what activity you'll do when the timer goes off. Something calibrated to wherever you happen to be that day: a walk or a coffee run at the office, cooking dinner or picking up a controller at home.
