The Digital Press

Ruby's JIT compilers, including YJIT and the newer ZJIT, speed up execution by compiling frequently called methods into native machine code while keeping the original bytecode for fallback and de-optimization.

Why it matters: JIT compilation boosts Ruby performance by converting hot methods to native code, improving execution speed.

The big picture: Ruby balances interpretation and compilation, profiling methods before JIT compiling to ensure efficient, accurate optimization.

The stakes: JIT assumptions can fail, triggering de-optimization to maintain correctness, especially with dynamic features like TracePoint or method redefinition.

Commenters say: Readers appreciate the clear explanation of Ruby's JIT internals, especially the balance between performance and correctness safeguards.