Worked on stabilizing EFI variable retrieval in the microsoft/mu_basecore repository, focusing on a critical bug fix within the index-table optimization path of FindVariableEx(). Addressed an issue where deleted variables could be incorrectly returned by implementing explicit state validation, ensuring only valid variables are processed and deleted entries are skipped. Enhanced the logic to prioritize valid variables when duplicates exist, improving boot-time reliability and correctness. Developed and integrated NVRAM-based tests to verify the updated behavior, maintaining backward compatibility for non-optimized paths. Utilized C programming, firmware development, and system programming skills to deliver a robust and maintainable solution for variable management.