Lead the design of user flows, interaction patterns, UI visuals and component behaviour Create high-fidelity designs, mockups, prototypes using tools like Figma, Sketch, AdobeXD Translate design assets into clean, modular, reusable React JS code Ensure front-end codebase adheres to best practices (performance, accessibility, responsive/mobile, maintainability) Define and own front-end architecture decisions Collaborate with UX researchers and product managers to validate design assumptions Help establish and maintain a design system, style guide, and shared component library Review peer code and design work, mentor junior engineers/designers