Ruby Outperforms C: Breaking the Catch-22
YJIT’s ability to improve performance by adapting to run-time behavior can increase the speed of our code in a way that dropping down to C can’t. As such, I think we should reconsider the common wisdom that “rewriting our Ruby in C” is the ideal path to performance optimization and take a serious look at “rewriting our C in Ruby” instead.
Source: railsatscale.com