Your objective is to find the limits of his capabilities, not have a polite conversation, but the interview shouldn’t be an overly stressful experience. The best interviews feel like intellectual discussions between friends (“What books are you reading right now?”). Questions should be large and complex, with a range of answers (to draw out the person’s thought process) that the interviewer can push back on (to see how the candidate stakes out and defends a position). It’s a good idea to reuse questions across candidates, so you can calibrate responses.
