Kielan M. focused on enhancing the stability and reliability of the rendering pipeline in the facebook/react-native repository during June 2025. Addressing a concurrency issue, Kielan identified and resolved a data race in the updateRendering function by introducing atomic operations for thread-safe access to eventTimingDelegate_. This fix unblocked previously failing tests and improved the robustness of the native rendering path. Working primarily in C++ and leveraging expertise in concurrency and performance optimization, Kielan’s contribution removed a critical race condition, resulting in more stable rendering behavior and increased test reliability. The work demonstrated careful debugging and low-level systems proficiency.