Over a two-month period, contributed to jdx/mise and hapifhir/hapi-fhir by delivering targeted improvements in cross-platform development and frontend engineering. Addressed a persistent issue in jdx/mise by refactoring Python executable path resolution, ensuring reliable virtual environment creation and version checks across Windows, macOS, and Linux, which improved CI reliability and streamlined developer onboarding. In hapifhir/hapi-fhir, enhanced the DateTimePicker component to support flexible date formatting through a data attribute, reducing client-side formatting code and simplifying localization. Demonstrated proficiency in JavaScript, Rust, and configuration management, with a focus on maintainable solutions that minimize regression risk and support diverse user needs.