During September 2025, Koshelev focused on technical debt reduction in the facebook/fbthrift repository by addressing the deprecation of the Thrift Reflection API. He reorganized the reflection module and deprecated additional reflection functions, targeting outdated struct dependencies and suppressing deprecation warnings. This work involved careful C++ code refactoring and library maintenance to improve long-term maintainability and reduce the risk of future refactors. By applying targeted changes, including marking more reflection functions as deprecated, Koshelev reduced warning noise and risk exposure related to deprecated APIs. His efforts contributed to a cleaner, more maintainable codebase using C++ and modern refactoring practices.