Worked on the alibaba/fastjson2 repository to enhance the robustness of enum deserialization, specifically addressing scenarios where the enum’s valueField is of Integer type. The solution involved converting non-String values to String before storage, enabling the parser to correctly handle JSON strings representing integer-based enums. This adjustment improved compatibility when consuming APIs that encode enum values as strings of integers, reducing potential production issues. The work was delivered with targeted unit tests to verify correct parsing and ensure reliability. Java and Kotlin were used throughout, with a focus on enum handling, JSON deserialization, and comprehensive test coverage to strengthen the codebase.