Kamil Wang

Designed and delivered a commerce-ready marketplace prototype enabling vendors to publish 3 product types and process payments via Stripe, achieving MVP in 8 weeks and reducing time-to-demo by 60%. Implemented responsive storefront and product management UI using React, Next.js, and TypeScript; improved mobile Lighthouse score by 33% across 150+ pages. Architected server-side APIs in Node.js and Express with PostgreSQL for product catalog, cart persistence, and order history; supported 10k simulated orders in load tests. Built admin dashboard for vendor accounts and moderating forums with JWT/RBAC; automated moderation and event management; reduced workflow time by 45%. Integrated transactional emails with SendGrid; implemented PCI-compliant payment tokenization with Stripe; reduced failed payments by 27% in staging. Optimized backend performance with Redis caching; migrated file storage to AWS S3 with signed URLs; improved uploader reliability. Orchestrated CI/CD pipelines with GitHub

Designed and shipped community modules including discussion forums and a markdown blog editor using React, TypeScript and Tailwind CSS; increased user engagement metrics by 42% in pilot cohorts. Built an event calendar UI with iCal export and Google Calendar sync via REST endpoints, enabling 1-click RSVP for 200+ hosted events. Enhanced checkout UI and client-side validation for payments using Stripe Elements, reducing cart abandonment by 18% across A/B tests with 3,000 users. Automated accessibility audits and remediation workflow for WCAG issues, raising accessibility score to 92% across core pages and reducing backlog by 70%.

Reduced page load times by 46% by refactoring large monolithic bundles into lazy-loaded React components and adopting TypeScript for stricter builds across 120+ pages. Established product detail and cart flows with persistent local storage and server-side reconciliation, resulting in 2.4x faster cart recovery for signed-in users over 6 months. Managed front-end testing and automated those tasks with Jest and React Testing Library, achieving 78% unit test coverage. Collaborated with designers using Figma to translate responsive UI into reusable components, shortening design-to-dev cycle from 10 days to 4 days. Mentored two junior engineers on TypeScript and accessibility best practices, raising team delivery velocity by 22%. Documented component APIs and workflows; reduced onboarding time for new hires from 7 days to 3 days.