Developed OS-level custom cursor support for the emilk/egui repository, enabling applications to use RGBA bitmap cursors for enhanced user interface flexibility. Leveraging Rust and graphics programming expertise, introduced a new API surface that allows per-frame cursor updates with efficient memory reuse via Arc<[u8]>. The implementation integrated seamlessly with egui_winit and ActiveEventLoop, ensuring robust cross-backend compatibility and safe fallback behavior for unsupported contexts. Quality was validated through comprehensive cargo fmt, clippy, and documentation checks, and the feature was demonstrated with real-world skin scenarios, improving the platform-native feel and supporting advanced UI development for custom-skinned applications.