I see you mentioned expanding in depth during the interview. That is closest to my personal style of interviewing.

I usually am looking for enthusiasm for a problem, depth of knowledge on that problem, and a willingness to admit the limits to their knowledge. My strategy is to keep asking probing questions about an area of their previous work, going deeper and deeper, asking them to express why it is important, what they tried, and what they could also have tried.

Ideally, not only does the candidate infect you with their enthusiasm for the problem, but they teach you something.

At least in fast-paced software companies, I think these characteristics best determine someone’s likelihood of success. I think it selects for people that can get things done quickly using small teams.

That being said, interviewing is difficult and full of false positives and negatives. Companies like Amazon and Google bias their selection criteria to encourage false negatives — deeming them less risky than false positives — but that sadly does prevent many good people from getting through the door.