Worked on stability and reliability improvements for iOS within the microsoft/react-native-macos and software-mansion/react-native-reanimated repositories, focusing on concurrency and memory safety. Addressed a crash in iOS request operation cancellation by introducing mutex locks to ensure thread-safe access to operation queues, effectively resolving race conditions and enhancing network operation reliability. In the Reanimated project, fixed an intermittent crash in the IOSUIScheduler by using a weak reference to self within asynchronous dispatch blocks, preventing dangling pointers and improving UI scheduling stability. Leveraged C++, Objective-C++, and concurrency techniques to deliver targeted bug fixes that reduced crash risk and improved user experience.