Worked on the airbnb/lottie-ios repository to address a critical animation issue affecting mask timing on precomp layers. Focused on stabilizing animation playback by fixing timing discrepancies that previously caused jitter and reduced visual fidelity across iOS devices. Utilized Swift and SwiftUI to debug and resolve the bug, collaborating closely with other contributors to validate the solution across multiple device configurations. Documented the changes thoroughly, including release notes and a validation plan, to ensure maintainability and regression-free deployments. This work improved the smoothness of Lottie animations, enhancing the overall user experience and supporting future animation pipeline stability in iOS development.