Worked on the PX4/PX4-Autopilot repository to enhance safety and reliability in flight control systems by addressing a critical activation bug. Developed C++ logic to prevent stale cached control setpoints from influencing new activations, introducing time-stamped cache writes and gating mechanisms to ensure only fresh data is used during mode transitions. Implemented a safe-default contract that maintains system stability until valid data arrives, with clear observability through per-activation warnings. This approach improved determinism and troubleshooting during external mode changes. Demonstrated expertise in embedded systems, safety-critical C++ development, and cache invalidation strategies within a complex flight control software environment.