How is it slow? At least compared to similar kind of projects? It is most definitely not a CRUD app you can just throw more devs at.

The project is quite young and already has a JS interpreter that is on-par with V8 when warmed up, and a Ruby interpreter that is roughly 3x faster then the next fastest one. Oh and in the meanwhile, they can run optimizations across language boundaries, that’s just insanely cool!

Sure, the good performance is partially due to the underlying JVM that has seen plenty of development time, but I think that Graal develops in a decent pace.

I was first introduced via TruffleRuby. But since then it's become less clear to me how viable TruffleRuby is versus JRuby.