The Setup
Before the interview, ask the candidate to send a one-page summary of a real problem they personally worked on. One hour. Any format. No template. A real problem, real ownership, real outcome.
The constraint does most of the work.
In the interview — the document becomes the script
Choice
Why this problem over everything else you could have picked?
Rejection
What did you consider and rule out — can you explain that quickly?
Shift
What changed between your first read of the situation and how it ended up being solved?
Hindsight
What would you do differently now?
No hypotheticals. Every question comes from the page. Hard to rehearse because it's grounded in something that actually happened.