Worked on evervault-js to enhance reliability and cross-origin payment support, focusing on resolving Apple Pay merchant validation issues in embedded merchant stores. Addressed a bug where domain validation failed in cross-origin iframes by ensuring the Apple Pay SDK used the top-level document’s origin, preventing checkout failures for merchants. The solution involved careful handling of cross-origin contexts and secure integration with Apple Pay, demonstrating a strong grasp of front end development and testing practices. Utilized TypeScript throughout the process, contributing a targeted fix that stabilized the Apple Pay flow for merchants embedding payment functionality within their applications using evervault-js.