> I highly doubt that your job is slow because Go and fast because Rust, it's slow because process/idiots in other teams/idiots in your team/idiots as your "agile coach" etc.
Team dynamics are of course, very important. But my job is slow absolutely because I don't have hot loading. Sure, yes, I could build hotloading in Rust, but it would be difficult and the resulting code would look be a lot less idiomatic than my Rust code is already; which makes it harder to do.
Because I don't have hotloading and I work with a system where long lived tasks stay on a single server, I can't change the code for existing tasks in progress. Instead, I have to set up a new cluster and let new tasks start on the new cluster, and then I have to later come in and cleanup the old cluster. This is a lot more work than pushing and loading new code on the existing cluster. And it means I need to wait longer to see the results. And tasks have a limited lifetime. Because of the operational cost of doing an update, it's not worthwhile to do small incremental updates, instead I have to batch things into substantial updates and keep track of more things.
At my previous job, we would regularly have tcp connected clients connected for weeks or months with the latest server code via hotloading. I can't do that now. Either I let clients stay connected to old code servers, or I force them to reconnect and lose their state. (Yeah, maybe there's a way to force them to reconnect and transfer their state; that's not easy though)
It's like making a mechanic work without powertools. Yes, you can do everything, but without the proper tools to do my job, everything takes longer. A mechanic trained without access to or knowledge of power tools might not notice the difference, of course. And power tools offer the ability to do both good work and bad work much faster.
Edit to add:
Re the job is to solve problems regardless of language; I don't necessarily disagree, and I'm definitely willing to pitch in and debug nearby systems that are outside of my preferred language, or even write code in a language I despise if it's the best way to solve a problem. But if the majority of my job is in languages that make it harder for me to work, and that's not something that was clear before I took the job, and especially if it's a new thing, it's going to make me look for something else. I'd expect that just as much for someone who feels Erlang makes them more productive as for someone who feels Rust or Java or C or Erlang or Fortran or Lisp or Python or whatever language they love. There's a lot to like about a lot of languages, even if they don't appeal to me.