Worked on the firecracker-microvm/firecracker repository to enhance virtualization reliability by improving snapshot serialization for KVM custom MSRs. Focused on Rust-based system programming, the developer replaced per-entry MSR handling with a range-based approach, ensuring the full spectrum of KVM custom MSRs was captured during VM snapshots. This technical refinement addressed previous omissions of critical MSRs, such as MSR_KVM_ASYNC_PF_INT and MSR_KVM_KVM_ASYNC_PF_ACK, thereby supporting more accurate VM state transfer during live migration and crash recovery. The work demonstrated deep understanding of low-level virtualization and x86_64 MSR management, resulting in maintainable code with minimal impact on existing APIs.