It really depends on so many factors it’s extremely hard to tell. We’ve brought folks at Cloudflare up to speed roughly that fast.

“average” and “proficient” are both very variable in that statement, imho.

They started with >1 Klabnik units and every person you bring up, it creates a larger pool of folks to lean on for support.

I can’t take credit here, while I am around to answer questions, getting folks going is not my job.

It is true that we have a chat room with a bunch of folks, of which I’m part.

I wouldn't discount what gp is saying though - having an (or a few) experts on hand from the start, can help training the first new convert "the right way" and they can then mentor the next one and so on.

Even just by being availabletto answer questions or help with code review. Doing some pair programming sessions would probably be useful too.

Oh yeah, it’s helpful for sure. I just don’t want to take too much credit!

For me it was 3 to 4 months, I had switched from Golang to Rust. Its been 8 months now and I believe that I have hang of things now.

Depends on your definition of average: I found that to be the case with significant programming experience with traditional languages (notably not something like Haskell) so I think it’s plausible since the compiler, editor, and documentation are rather above average for newcomers. In particular, Cargo providing a lot of easy tools and the compiler providing really helpful error messages seemed to be useful for the time to write a real first program which does something useful.

Edit: one other big factor - presumably in their environment you have coworkers to get advice from. That’s huge when you’re first starting.

And your definition of “proficient”!

Yes, I’m using it in the sense of “can successfully develop a program which does the job” with the assumption that it’ll still take more time to do it quickly, use more advanced techniques, etc.

We became pretty comfy with it in less than a month in Aug 2017. (Let's say average guy had a few years of Python and this-and-that before that, and a ~5 year CS degree before that.) Sure, there was no async/await anywhere yet, but no crossbeam-channels either. And there were a lot less friendly tutorials and there were a bit more rough edges. (Especially that we did "IoT" so cross-compiling was ... an experience.)

IME it takes 2-3 months for a talented senior developer to get comfortable with it.

”Several weeks of hard effort”, they said. I can buy it, if they actually work hard and are basically competent. Rust is a difficult language in total, that’s for sure, but you can get a lot done without knowing it all.