Java, Go and C# (and node) have very similar performance, e.g. https://benchmarksgame-team.pages.debian.net/benchmarksgame/.... For all of them, the key to writing high performance code is avoiding allocations and boxing. Go and C# both do this slightly better than Java, but in most domains where these languages are used, this is not a big difference (and this is where you might use C/C++/Rust instead). I've found Go to be more verbose than Java, but I haven't used Go much since generics were released.