Worked on enhancing Bluetooth periodic advertising lifecycle management in the nrfconnect/sdk-zephyr repository, focusing on API flexibility and host stack stability. Developed a new C API to allow unregistration of periodic advertising sync callbacks, addressing the need for safe callback list iteration and reducing risks of concurrent modification. Expanded the project’s test coverage by implementing regression tests and a dedicated Bash validation script to ensure robust unregistration behavior. Leveraged expertise in Bluetooth development, embedded systems, and testing frameworks to deliver a targeted feature that improves reliability in dynamic environments, while maintaining a disciplined approach to code quality and validation throughout the process.