I’ve done both Swift and rust for Linux applications (symbolic analysis tools and compilers, not web stuff or other server apps). I have to say, I’m torn after building a couple moderate (10-30k SLOC) scale tools in both. I prefer swift since I feel like I’m working at the abstraction level I prefer and letting the ARC stuff take care of memory for me. Rust isn’t so bad, but it does make me think more about things that I don’t when I’m in Ocaml or Swift. Rust has better tooling: the LSP support makes life nice in emacs. Compiler feedback and clippy : super useful. Not a fan of the high usage of crates (I’m in the paranoid about supply chain camp). Swift felt like it shipped with more batteries included. I think the main factor is the people side: however much I like swift, I’m more likely to find rust people in my world. I’m rooting for swift though: the world has room for more than one memory safe C++ successor.