[Fritsdehacker]

Why would threading with GIL be worse than no threading at all?

As long as IO is your bottleneck the GIL shouldn't be much of a problem. And Python (and I'm sure Ruby, too) has excellent async support.

Not saying Node.js isn't useful, but I wouldn't automatically say no to Python or Ruby.

[l1ambda]

Fair point. I would probably use a multiprocessing approach in node.js or use https://www.npmjs.com/package/webworker-threads. If perf were very critical I would use Rust.