Worked on enhancing code quality in the optuna/optuna repository by refactoring string formatting throughout the codebase to use Python f-strings. This update improved both readability and potential performance, aligning the project with modern Python standards and reducing long-term technical debt. The work focused on maintainability, making the codebase more accessible for contributors and easing future onboarding. No bug fixes were addressed during this period, as efforts centered on systematic code refactoring. Utilized Python programming and code refactoring skills to implement these changes, ensuring that the repository’s formatting practices are consistent and up to date with current best practices.