During April 2025, Mercury focused on backend reliability improvements for the Adyen/adyen-node-api-library repository. He addressed deserialization issues in webhook transfer tracking by refining how union types are instantiated based on the event’s type field, ensuring accurate handling of transfer events. Mercury enhanced test coverage to validate both union deserialization and date field conversions, reducing the risk of future regressions. His work included targeted code cleanup, removing unused code and improving repository formatting while maintaining full API compatibility. Throughout the month, Mercury applied his expertise in TypeScript, API integration, and backend development to deliver robust, maintainable solutions without introducing new features.