> "what's the favorite bug you've ever fixed?"

I use a variant, "What's the most memorable bug you've fixed?" - and I use it as an indicator of maturity to distinguish L3 SwE from a L5+ SwE (google levels).

First, there is the time-in-field aspect. Simply being in the field for a long time increases the amount of time you have to encounter a sleep-depriving bug.

It can show tenacity. How did they find it? What did they have to do to reproduce it? Was it in prod, test, or dev? etc.

It can show maturity. Why did it pass test? What tests were introduced to detect it? Was it a new class of bug that required new testing? Were you able to add lint rules to detect it? Did you ensure it was pushed properly to prod and do proper follow up.

It can show autonomy. Did you update the testing procedures or just post a bug and hope the QA team fixed it? Did you meet with devops and share info on how to detect and mitigate it? Did you update the playbook at least?

So many possible places to dig in to get the "hire" when the default answer is "no hire". And if you cannot find any, then that's confirmation of the default answer.