Hacker News Reader

Yes but it would just be the hot loop in this case; the rest of the app can still be in idiomatic Java, and you still get the GC.

Exactly. Write it in Java, optimize what you need to, leave the rest alone.

As polyglot dev, I never understood this religious approach that it has to be 100% pure unadulterated in language XYZ for performance.

Nope, embrace the productivity of managed languages, if really needed, package that rest in a native library, done.