The language does do great at the core of it, but there's a lot of stuff that makes it easier that's not the language's job.

compare https://doc.rust-lang.org/1.2.0/book/rust-inside-other-langu... to http://usehelix.com/ for example; the former is only using what the language knows, the latter is a nice library built on top.

There's been some effort for nicer Python integration, but I haven't seen anything super super slick yet.