Xinlong Wang developed the Perpetual Contracts Banner Support feature for the OneKeyHQ/app-monorepo, enhancing the Market section with a new banner type and integrated route for perps token lists. He implemented a dedicated API endpoint and a React-based UI component to display token data, including leverage, funding rate, and open interest. His approach emphasized maintainability by refactoring code into reusable hooks and components, while also improving security through input encoding and optimizing data freshness with polling. Using JavaScript and TypeScript, Xinlong aligned the new feature with existing architecture, documented changes for cross-team use, and focused on robust, scalable front end development.