During June 2025, this developer created a MacOS Screen Brightness Library for the facebook/buck2-prelude repository, focusing on cross-platform display management. The library enables both hardware-level brightness control using DDC and software-based adjustments via gamma tables, addressing the needs of external and built-in Mac displays. By leveraging private APIs, the solution extends support to integrated screens, ensuring comprehensive brightness management across devices. The work involved system programming and framework integration, with Bzl as the primary language. The resulting module is designed for reusability, laying the groundwork for future enhancements to Buck2 developer tooling related to display and monitor settings.