When is JIT Faster Than A Compiler? - Shopify

What this post added

This post introduces YJIT, a Just-In-Time compiler for Ruby, and explains the fundamental differences between interpreters, ahead-of-time compilers, and JIT compilers. It details how JIT compilers can achieve performance gains by making runtime assumptions about code behavior (e.g., method definitions) and de-optimizing when these assumptions are violated, which is particularly beneficial for dynamic languages like Ruby where code can be redefined at runtime. The post highlights the challenges of compiling Ruby due to its dynamic nature and explains how YJIT addresses these by selectively compiling code and invalidating it when necessary. It also provides information on how to try out YJIT and its current development status.