My second ever job was at a startup that put me through three rounds of interviews, all of them in Python. The homework task, the questions, literally nothing else was mentioned through the entire process.
After I got hired, I showed up the first day and one of the managers asks me, "So I heard you know functional programming, right?"
I said "yes" and was immediately whisked off to the backend division that worked entirely in Scala, a language I had literally never spent more than 5 minutes on before dismissing because the online tutorial I was using broke about two chapters in.
Is it unusual? I’ve changed jobs three times now going into places with different languages than ones I had much experience of. IME it takes about as much time to learn the codebase as it does to learn a new language and both go hand in glove.
IME it depends on the shop and it's own skill level. If you've got a bunch of devs with only experience in the tech stack the company is using, they'll be heavily selective for a match to their stack. If they've got a broad set of internal tools in a bunch of languages, they're likely selecting more broadly based on overall skill or the ability to get up to speed.
And I'm 100% with you there, learning a new place's codebase can often take as much or more time than learning a new language (at least if you've got experience with a couple of languages already). There's at least tutorials and guides for a new language, and there's rarely good docs and resources for the codebase.
After I got hired, I showed up the first day and one of the managers asks me, "So I heard you know functional programming, right?"
I said "yes" and was immediately whisked off to the backend division that worked entirely in Scala, a language I had literally never spent more than 5 minutes on before dismissing because the online tutorial I was using broke about two chapters in.