Marvin Stenger enhanced the Go compiler in the golang/go repository by developing and integrating two new boolean expression simplification rules, replacing the previous single rule to address a broader range of cases. Working in Go and applying principles of compiler design, Marvin’s changes improved both the performance and correctness of boolean optimizations within cmd/compile. The implementation involved careful analysis of existing logic, code refactoring, and thorough cross-team code reviews to ensure maintainability and adherence to Go’s development standards. This work deepened the compiler’s optimization capabilities, enabling more efficient handling of boolean expressions and contributing to the robustness of the codebase.