[matthewmacleod]

This varies from language to language, and from role to role.

If I'm hiring for someone mostly working with Go, I'm not going to be that bothered if they only have experience with e.g. Java, Ruby, and some Typescript. It's a language that's almost explicitly designed to be easy to pick up and work with, and I'd be confident that a developer with a few years of experience would be able to become productive pretty quickly.

If it's about working with C++, that's probably different. In my experience, there's so much hidden knowledge in there that engineers with no previous contact are really going to struggle. I've found it's better in that situation to allow developers from other teams to explore and contribute to the codebase and learn from others as they develop their skills.

Similarly I'm unlikely to hire a frontend with no previous frontend experience, regardless of language – but if you were previously working on games and now want to do robotics, there is probably enough overlap to get started.

TLDR one size does not fit all.