Worked on enhancing the reliability and type safety of column statistics within the ydb-platform/ydb repository, focusing on histogram evaluation. The main contribution involved refactoring the histogram handling logic by replacing std::optional with TMaybe, a change that improved both correctness and maintainability of the codebase. This targeted update addressed type safety concerns and clarified the evaluation process for column statistics, supporting more robust data processing workflows. The work was implemented using C++ and leveraged skills in data processing and statistical analysis. Over the course of the month, the developer delivered this feature without addressing bug fixes, emphasizing careful, focused engineering improvements.