Worked on stabilizing memory mapping in the microsoft/openvmm hypervisor project by addressing a critical bug in MSHV guest PFN handling. Focused on low-level system programming, the developer corrected the derivation of guest PFNs by right-shifting guest addresses, ensuring valid parameters for memory mapping and preventing hypercall failures. This patch improved runtime reliability and reduced errors during guest memory operations. The work demonstrated strong debugging skills and attention to code quality, with clear commit documentation and alignment to project issues. Technologies used included Rust, C/C++ debugging, and hypervisor interface development, emphasizing robust memory management and integration within the codebase.