I came across an episode of the Vector podcast, where Rene Ritchie interviewed Don Melton on team building. It's a wonderful, timeless episode on what it takes to build a great team. (Go listen to it!)
One section resonated really deeply with me, where Don talks about what he'd look for when he interviewed candidates at Apple. It takes place about 14 minutes in to the show:
This is what I've found, and I've actually used this over the years:
Smart is greater than Knowledgeable.
Intelligence and problem-solving skills are [almost] always more valuable than specific domain knowledge... That's because domain knowledge changes over time; it gets stale - and I would rather have a whole team of generalists than just a few specialists.
You have to have people who are able to be generalists, because they can reapply what they know to new problem domains... you can be flexible like that.
Being Teachable is even better than being Smart. You have to ask yourself: can you teach them, even if they're not mart now? Can they learn quickly, and eventually become experts? Do they have headroom? Can they grow?
So, Teachable is even more important than being Smart.
There's something that's even more valuable than being "Teachable", and that's being Passionate. You have to ask - will they do it? If you have somebody that's Knowledgeable, that's Intelligent, that's Teachable - are they going to go for the long haul? Are they willing to make the effort? Because people on a mission like that are not to be trifled with - they're The Crazy Ones. Passion - it's so important - it's this little burning seed in there, you've got to have the "fire in the belly" - very, very important.
What I've found over the years that trumps all, that trumps even Passionate, has always been Trust. Are they trustworthy? It actually might be even more important than Passionate. Can I trust this person to finish the job, to complete what they said they'd do? It's absolutely the hardest thing to evaluate in a job interview, you've got like 30-45 minutes with a person, how do you do that?
(Teachability is also difficult to evaluate in an interview, but it's nowhere near as [difficult] as Trustworthiness.)
You really have to learn to peer into the soul of people to try to figure [Trustworthiness] out, but it also helps if you know some history. It really helps if you know the candidate personally, or if someone you already trust knows them and knows them to be trustworthy.
Hiring someone you Trust, by the way - it's just fabulous, because Trust is peace of mind at night, because you can actually go to bed and get a good night's sleep, because you can trust that person to come through. It's a delight.
Seriously, go listen to this episode.