During April 2025, Lee focused on performance optimization within the Samsung/TizenFX repository, specifically targeting the NUI string handling path. Lee refactored the LowerFirstLetter function in C# to use unsafe character array access, reducing unnecessary string allocations and eliminating reliance on StringBuilder. By introducing early returns for null or empty strings and for cases where the first character was already lowercase, Lee streamlined the function’s execution and improved UI string processing efficiency. This work demonstrated depth in low-level programming and string manipulation, delivering a focused, maintainable solution that addressed a clear performance bottleneck without introducing additional complexity or risk.