Worked on the renesas/zephyr repository to resolve a critical C++ runtime linkage issue encountered when building with LLVM. Addressed this by updating CMake build configuration to ensure the correct compile flags were applied and the appropriate C++ runtime library was selected, which prevented problems with RTTI and exception handling. This fix improved the stability and reliability of Zephyr builds using the LLVM toolchain, reducing both build-time and runtime errors for downstream users. Demonstrated expertise in cross-platform development, CMake scripting, and runtime library selection, contributing to the long-term maintainability and compatibility of the project across different toolchains.