Yitao focused on security hardening for the All-Hands-AI/agent-sdk repository by addressing a denial-of-service vulnerability in the Rich package. He upgraded the dependency to Rich version 14.3.3 and tightened dependency constraints to ensure the vulnerability could not reoccur, prioritizing both security and build stability. Using Python and leveraging his expertise in dependency management and security updates, Yitao delivered a focused, auditable change set that preserved the integrity of the build process. His work demonstrated careful risk mitigation and clear traceability, resulting in a safer codebase without introducing new features or instability during the month’s development cycle.