Worked on the ydb-platform/ydb repository to enhance type safety and maintainability within the codebase. Focused on refactoring type annotation handling by replacing raw pointers with const references, this approach reduced the risk of null pointer dereference and established a safer foundation for future pointer management features such as TCheckedDerefPtr. The work involved careful C++ development and code refactoring, emphasizing type safety as a core principle. By prioritizing const-reference usage, the changes improved code reliability and prepared the system for more robust pointer dereferencing mechanisms in upcoming iterations, reflecting a methodical and safety-oriented engineering approach throughout the development process.