Worked on the Automattic/jetpack repository to enhance the stability and user experience of the Critical CSS progress bar during CSS generation. Addressed a key bug by implementing safeguards that prevent the progress bar from moving backward, ensuring it always fills to 100 percent. Introduced a hold timer to visually indicate completion before transitioning to the finished state, reducing user confusion and improving workflow reliability. Collaborated with other contributors to maintain code quality and consistency. Utilized React for front end development, leveraging both JavaScript and TypeScript to deliver a targeted fix that improved the perceived performance and reliability of the process.