Worked on the Adyen/adyen-node-api-library repository, focusing on backend reliability and code quality for webhook handling related to transfer events. Addressed a deserialization issue by refining how union types are processed in webhook transfer tracking, ensuring the correct instantiation of tracking types based on the 'type' field. Enhanced test coverage to validate union deserialization and date field conversions, reducing the risk of regression. Performed code cleanup by removing unused code and improving repository formatting, while maintaining existing API behavior and compatibility. Utilized TypeScript and backend development skills, with an emphasis on robust API integration and maintainable, well-tested code.