For anything "slow" I can put it in Sidekiq and just run the worker code with TruffleRuby.
I have high hopes for ZJIT but I think TruffleRuby is the project that proves that Ruby the language doesn't have to be slow and the project is still getting better.
If ZJIT, JRuby or TruffleRuby can get within 5-10% of speed of Go without having to rewrite code I would be very happy. I don't think TruffleRuby is far off that now.