What are your thoughts about candidates who code correct solutions in a language not in use at your workplace?
I have a nagging feeling that some positions in my group have gone unfilled due to tech stack mismatches in candidates who were probably perfectly capable (or better) coders, but were most recently working in other tech stacks. Considering these types of candidates seems to be challenging in my workplace.
I think it's a big mistake to avoid hiring a Python programmer because they don't know Ruby, but it's one people seem happy to make, even in otherwise relatively enlightened organizations.
Exception: first jobs and very inexperienced people. Basically if the answer is given in a specific language because they don't know any other and couldn't produce the answer you want after short time of studying relevant docs, then it may be a real problem.
I suppose the only thing that would make me frown is if the candidate was evidently a huge language zealot and wanted to use nothing but their language of choice. But I've never interviewed such a person actually.
Well worth it if the alternative is hiring someone who knows the language/framework you're working in, but pretty much only knows that language/framework.