Worked on the google/perfetto repository to enhance the AndroidInputEvent proto by introducing an explicit typedef for the key_code field. This change, implemented using protobuf and proto definition skills, improved type safety and clarity in the event model without altering runtime behavior or breaking backward compatibility. The update clarified the API contract, reducing the risk of misinterpretation for downstream consumers and supporting future refactoring efforts. Focus was placed on maintainability and reliability, with documentation updated and code prepared for review. No bugs were fixed during this period, as efforts centered on strengthening the foundation for safer Android input event handling.