Sole designer on Wix's eCommerce platform, owning end-to-end UX for checkout and commerce surfaces used by millions of business owners worldwide. I initiated the checkout revamp myself - identifying that the UI had fallen behind industry standards, quantifying the opportunity at $31M per point of conversion, and leading an eleven-person cross-functional team to ship it across 11 verticals. Built the Slot System behind the Side Cart, aligning Stores, Restaurants and Bookings on shared extension points, and established the platform's design-system libraries. Integrated AI into the team's workflow and applied hands-on CSS on live sites.