[Jach]

Another great answer for many things is "It depends". :)

I don't have an issue with your approach (I think interviewers who think about the issue at all and occasionally tweak things are going to do better than those who don't) and the fuller version makes it pretty clear that the goal is to create a feeling of getting along well. For many companies the candidate is also interested in that information, but at other companies it doesn't really matter because if hired the two won't actually work with each other, or it will be brief as the new hire changes teams.

I don't do pairing in my interviews but I've thought about it. Before doing it for real I'd want to pair with a coworker on a problem neither of us have solved before, which will happen naturally if pairing is part of the company culture, then pair with them later on a problem I had previously solved but they had not, and see what differences in my own behavior (if any) appear when I have one of the possible solutions in mind. That's my main concern with doing it with a candidate, that the balance on one side of the pair for driving things is just not natural to the usual setting.

You could eliminate that concern by always using a novel problem to yourself (I've got a handful of problems I know something about but have never tried to solve, I do think it'd be fun to try and solve them with a candidate) but then there's the secondary concern in that by the end of it do you really have anything you can say besides "I do/do not get along with them and think we'd work well together"? I like to be able to say a little bit more than that, and also to create the opportunity to say "I like both of these candidates, can't say which one more, they both passed the threshold of solving the problem's basic case, but this one's code covered an extra edge case without me pointing it out." It happens that sometimes I can't even say that, of course, and multiple candidates are equivalent on the criteria I measured. But sometimes it's fine, you just care about some basic threshold, and you can just extend the offer to the first person that satisfies. I think this is probably the case more than many companies big and small want to admit.