Worked on stabilizing Vsync initialization within the Flutter engine for the Fuchsia platform, focusing on eliminating redundant initial Vsync callbacks when the display is off. Addressed this by implementing a one-time guard, MaybeRunInitialVsyncCallback, in the flutter/engine repository and ensuring its propagation through engine-flutter-autoroll/flutter to maintain consistency during engine rolls. Utilized C++ and system programming skills to introduce a flag that prevents repeated callback execution, thereby improving startup and runtime stability. The work emphasized callback handling, multithreading, and performance optimization, resulting in enhanced reliability and smoother updates for devices running Flutter on Fuchsia.