During April 2025, Lei Chen focused on strengthening the Bluetooth stack within the apache/nuttx repository, addressing critical reliability and security concerns in embedded systems. Working primarily in C, Lei identified and resolved issues related to buffer overflows and protocol misbehavior, specifically by implementing robust ACL data packet length validation and correcting H4 header and data buffer checks. The work also included improving HCI response handling to ensure proper error logging and propagation. Drawing on expertise in Bluetooth and driver development, Lei’s contributions enhanced the stack’s resilience, demonstrating a deep understanding of embedded system constraints and the importance of defensive programming.