See the post is about using Rust on the frontend. In my opinion it is not a suitable place for Go or Rust due to their large runtimes that needs to be transpiled. Even with webassembly the Runtime size would be huge. So it is not suited for the frontend. As far as backend is concerned the decreasing order of difficulty to write the same code seems something like this to me Rust -> Haskell -> Go -> Ruby -> Clojure.