It seems odd to willfulky ignore Crystal language when discussing Ruby and speeding it up. Granted, macro semantics mean something else, more like c macros, but the general syntax and flow of Crystal is basically Ruby. https://crystal-lang.org/

Amber and Lucky are 2 mature frameworks to give Rails a run for their money, and Kemal is your Sinatra.

https://docs.amberframework.org/amber

https://luckyframework.org/

https://kemalcr.com/