Worked on the optuna/optuna repository to enhance code quality within the ranking module by modernizing string formatting practices. Focused on refactoring _rank.py, replacing legacy .format() calls with Python f-strings to improve code readability and reduce the risk of formatting errors. This update aligned the codebase with current Python standards and laid the foundation for future maintainability. The work was delivered as a single, well-documented commit, facilitating straightforward code review and traceability. Leveraged skills in Python and code refactoring to ensure the ranking logic became clearer and more robust, supporting ongoing improvements in code quality and maintainability.