30 seconds of theory before you start
The first answer almost always sounds good. Real understanding shows on the second and third follow-up.
Strong questions
- «How exactly did you do it?»
- «Why this way and not another? What were the options?»
- «What would you do differently now?»
The usual miss
Jumping to a new subject after the first confident answer.
You're done when
You reached the level where the candidate ran out of details, or made sure they have enough.