I have to disagree with your “when use what” list. Python has production ready web backend frameworks, Rust is perfectly fine for complex and high-level software, and PHP is mostly obsolete. That’s my humble opinion though. I looked into Nim and like many of the concepts. It’s quite complex and I prefer Rust most of the time when Nim would be an option. I’d argue it’s some kind of “jack of all trades”. A bit like python but compiled, ref-counted, and probably a lot faster. It’s lacking the huge community python has though.