Worked on the optuna/optuna repository to enhance the FrozenTrial module by refactoring its string formatting logic. The approach involved replacing legacy .format calls with modern Python f-strings, improving both code readability and performance. During this process, a minor bug introduced by the refactor was promptly identified and resolved, ensuring correctness in the module’s string construction. The changes aligned with ongoing code quality initiatives, contributing to reduced maintenance costs and greater consistency across the codebase. This work demonstrated proficiency in Python and code refactoring, with a focus on maintainability and robustness in the representation of core data structures.