Concurrency, as in multiple OS threads communicating is nicely done, with the borrow checker being able prevent some fairly common multi-thread pitfalls. So for

Concurrency, as in multiple OS threads communicating is nicely done, with the borrow checker being able prevent some fairly common multi-thread pitfalls. So for things like data parallelism etc. Rust is already looking pretty good. For server-side stuff, what's not yet done is some infrastructure and improved ergonomics for writing asynchronous or non-blocking code. See https://areweasyncyet.rs/ https://areweasyncyet.rs/ . And then when the infrastructure is there, it'll take a while before the higher-level frameworks take advantage of it.