When is JIT Faster Than A Compiler? - Shopify

This post explains the fundamental differences between Ahead-Of-Time (AOT) compilers and Just-In-Time (JIT) compilers, particularly in the context of dynamic languages like Ruby. It details how JIT compilers leverage runtime information and de-optimization to achieve performance gains that AOT compilers struggle with due to the need for static correctness. The author, working on YJIT for CRuby, highlights Ruby's dynamic nature as a challenge for AOT compilation and explains how JITs can make assumptions about code behavior that are later invalidated and corrected. The post also provides information on how to try out YJIT and its development status.