Arthur Breton worked on the MetaMask/metamask-mobile repository, focusing on a targeted data-flow cleanup for the Perps UI. He consolidated UI state management by removing redundant fee-related properties from PerpsClosePositionView and PerpsOrderView, and eliminated unused confirmation tracking from PerpsDeposit. Using React with JavaScript and TypeScript, Arthur streamlined the data models to reduce confusion and maintenance overhead. His work addressed dependency cleanup and aligned the codebase with broader refactoring goals, laying the foundation for faster feature iteration and lower regression risk. The depth of his contribution was in simplifying state management and improving maintainability for future Perps UI enhancements.