I've helped hire three different developers where I work now, and been a part of countless interviews. I've found it much more beneficial to look for people who think like programmers than know any given language. Unless you're talking really specific, deep stuff in a given language, the syntax and whatnot are trainable. What you can't really train people to do is take a large task that we want our software to accomplish, and break that up into pieces or steps that can be built. Nor can you teach the basic pragmatic techniques that go into things like using objects and classes.
We hired on someone who had barely touched Swift as he'd been out of the iOS environment for many a year, and even before that had never done a ton of app development, but he had solid fundamentals in other languages so I went to bat for him and got him hired. Not even 4 months later he's a top contributor on our team.
Spot on. Even too many developers think that their main skill is recall of language/platform/tool specific niche arcana, and while it's true that sometimes having that will reduce friction, it's rarely what actually drives things forward.
Arcana are concrete and relatively easy to test for, though, so my theory is that it's a bit like the story of looking for the keys by the lamppost because that's where the light is, even if you dropped them somewhere else.
(Didn't see this reply and it's an interesting question so excuse some necro)
For my case above, this devs experience with iOS was so minimal he didn't even have it on his resume, he listed himself solely as an Android developer (but like most places we develop for both, so it was useful experience regardless). I have a strong feeling most HN folks would absolutely interview like I do, but the problem is the interview is the last step of an otherwise highly bureaucratic process that is more or less entirely devoid of technically-minded people. Like, even the recruiter that got me my job many years ago, bless em I love where I work, but even that recruiter didn't know shit. They found me because I specialized in a lot of the things my employer was after, and that sounds alright, but that was solely based on the keywords: Swift, Objective-C, etc. A recruiter, for example, won't understand that someone fluent in Objective-C, while they're going to have an adjustment period, could probably competently write C, C#, or C++ as well with some help and training.
We hired on someone who had barely touched Swift as he'd been out of the iOS environment for many a year, and even before that had never done a ton of app development, but he had solid fundamentals in other languages so I went to bat for him and got him hired. Not even 4 months later he's a top contributor on our team.