Worked on the Shopify/ruby repository to address a critical bug in the YJIT compiler’s handling of local variable indices. Focused on backend development and compiler design using Ruby and Rust, the work involved implementing a fix to cap local variable indices above 255 to MAX_CTX_LOCALS, preventing overflow and incorrect aliasing in register mapping. This solution resolved an issue where high-index locals could be mis-mapped, ensuring correct JIT compilation and improved runtime stability for methods with many local variables. The contribution enhanced the reliability of local variable management in YJIT, reflecting a deep understanding of low-level compiler internals and runtime behavior.