This talk will go over the architecture overview of a JIT compiler written in Rust by Shopify, YJIT. While the optimization target is Ruby, I'll show only easy code that could be understood even if you haven't used Ruby. Also, I will not require any compiler-related knowledge to understand the talk so that anybody could enjoy this talk.

• How a JIT compiler works
• What is bytecode?
• Intermediate representation: We started using Rust to implement this easily.
• Codegen backend: x86_64, arm64
• Optimizations
• An overview of Basic Block Versioning: a JIT compiler design used by YJIT
• How Rust structs are used for optimizing Ruby's bytecode
• Challenges
• C <-> Rust interop: bindgen and lots of unsafe :)