Intelligence. Tenacity. Ambition. Judgement. Bonus points for recognizing the bullshit parade that is the current startup world. e.g.: NodeJS has value, but it's mostly the same wheel we've had for 20+ years. Or that MongoDB's changelog has consisted of standard SQL features for the past five years and that pgsql would have been just fine (had people read some boyce-codd anyhow).
How do you judge those qualities? I too interview for a similar set of skills (intelligence, curiosity, a desire to constantly improve things, someone who's just willing to put in the hard slog as well as work on the fun projects) but it's incredibly hard! I've definitely had people that interviewed well that just wanted JIRA tickets fed to them immediately upon starting. It's very hard to figure out if someone will…
I mean, what ambitious person would like to worse in less that best job available on the market, for best possible money?