Worked on security hardening and stability improvements in google/gvisor and google/bumble, focusing on concurrency safety, protocol validation, and buffer management. Addressed race conditions and TOCTOU vulnerabilities in gvisor by introducing proper locking and atomic counters, while enhancing TCP/IP stack compliance with RFC 5961 and limiting response payload sizes to prevent overflows. In bumble, implemented robust input validation and buffer controls for Bluetooth protocols, introducing error handling to mitigate malformed packet risks. Used Go and Python to deliver backend and systems programming solutions, emphasizing error handling, security best practices, and comprehensive testing to improve reliability across networking and Bluetooth stacks.