Worked on the nix-community/emacs-overlay repository to stabilize core parsing behavior for Elisp and Org mode Babel blocks. Addressed a regression by rolling back recent FromElisp parser changes, restoring the previous parsing logic to maintain compatibility with established user workflows. Used Nix to manage the rollback process, ensuring minimal disruption and reducing the risk of further issues. Focused on maintaining project stability and preventing support overhead by implementing a safe and targeted code reversion. The work emphasized careful change management and a deep understanding of the Nix language, prioritizing reliability and continuity for users relying on the emacs-overlay project.