Browser & Client-Side Testing: Experience building E2E test frameworks for browser extensions or other client-side commerce surfaces from scratch (page objects, extension-context fixtures, network/HAR-replay stubbing for anti-bot sites, cross-browser dispatch). Build and maintain test automation for commerce and marketplace surfaces, such as offers, cashback, affiliate/attribution and click-tracking accuracy, consent gates, and persona-based experiences (e.g., logged-in/out, member-group-specific offers), including client-side surfaces like browser extensions.