Worked on enhancing the stability and memory safety of the Zsh line editor (ZLE) within the zsh-users/zsh repository by addressing a critical bug in the refresh logic. Focused on correcting an incorrect array index decrement and ensuring proper memory deallocation during line rotations, which eliminated a memory leak and prevented potential heap corruption. This targeted fix improved the reliability and memory management of interactive editing sessions, especially under heavy workloads. Demonstrated strong skills in C, memory management, and systems programming while navigating a complex, widely-used codebase. The work contributed to ongoing efforts to harden the ZLE lifecycle for end users.