Worked on enhancing API compatibility in the open-feature/go-sdk-contrib repository by upgrading the Flagsmith client from version 4 to version 5. Focused on aligning the SDK with the latest Flagsmith API features, the work involved careful dependency management, compatibility validation, and comprehensive documentation to ensure traceability. Utilized Go for implementation and testing, emphasizing robust API integration practices. This upgrade reduced technical debt and improved the maintainability of the codebase, enabling downstream services to adopt new capabilities more easily. The effort laid a solid foundation for future feature development while minimizing maintenance risks and supporting ongoing interoperability improvements within the repository.