A while back we were hiring for a backend seat on a payments team, and one candidate looked like the strongest on paper. Near the end we asked the question we now put to everyone: tell us about something you broke in production. They said nothing came to mind, then offered a story where a release went wrong and QA had missed it.
We passed. Not over the incident itself (most people who ship code that moves money have one), but because the version they told had no version of themselves in it.
The person we did hire answered the same question with a duplicate-charge bug: what caused it, what the fix was, and what they added to the deploy checklist afterwards. That is the person you want reachable at 2am, because they already think in terms of what they can prevent next time.
We kept the question. It tells us more than the take-home task did.
What's the one interview question that tells you the most about someone?