Who said you need competence, looks like that was your own insertion, haha. But seriously is it not unreasonable to be able to write some non-deep dive code in a new but similar language in just a few days? 3 days is a long time to read and ask questions.
What purpose does it serve though? I think being able to read and understand a Go program is a better example. That does seem like a reasonable and useful ask in 3 days for a veteran PHP/Java dev, and something that is more likely to come up in practice. What is the context of the former? "Welcome to our team. I know we didn't hire you as a Go dev. You have 3 days to "be able to write Go".
I have long subscribed to "A programmer is not language specific", and I don't hire based on the languages you know. But that first task is "Here is access to the repo. Read and understand what our code does today please. I'll answer questions within reason." Acquiring the new language happens as a side effect.
If you hire someone in a language they don’t know, you expect them to learn on the job. It’s reasonable by day 3 to expect them to show some code - even if terrible.
I would say, most? Or maybe I have been really unlucky, lol! I don't think it is POSSIBLE for an employee at my current company to be productive before week 2.
