[cutler]

Really? Can you point me to details supporting this?

[sosodev]

Falcon, an async Ruby webserver, is a good example of scaling Ruby with fiber scheduling https://www.codeotaku.com/journal/2018-06/improving-ruby-con...

I'm not sure if Ractor has any real benchmarks yet but it enables genuine parallel Ruby code that communicates through message passing without too much overhead.