Seth Heinzman
Senior Frontend Engineer
Frontend engineer focused on e-commerce architecture, measurable web performance, and accessible customer experiences. At Havertys, I lead storefront engineering for a site serving roughly 1.75M users each month.
Technical Skills
Technologies I use to ship storefronts, measure their performance, and keep releases reliable.
Frontend
Professional Journey
Lead Frontend Developer
Technical lead for Havertys.com, responsible for storefront architecture, performance, accessibility, testing, and experimentation across a site serving roughly 1.75M users each month.
- Directed the migration from AEM React to Adobe Edge Delivery Services with Preact and TypeScript, simplifying the storefront architecture.
- Raised Lighthouse scores from roughly 30 to 90+ by addressing Core Web Vitals, including LCP and TTI.
- Delivered the cart, checkout, product detail, and product listing experiences with consistent behavior across the purchase journey.
- Launched an A/B testing workflow with Adobe Target and Analytics, giving product and marketing teams evidence for feature decisions.
- Introduced Jest and brought unit-test coverage above 80%, catching regressions earlier in the release cycle.
- Mentored three senior engineers on a six-person team, expanding ownership of architecture and feature delivery.
- Resolved more than 90% of identified accessibility issues while aligning the storefront with WCAG 2.1 AA.
- Defined shared UI patterns in Storybook to keep implementation and visual behavior consistent.
- Maintained business-critical Struts and Java tools while integrating them with the modern storefront.
React Developer (Consulting)
Primary frontend consultant for React applications, translating client requirements into maintainable interfaces and production releases.
- Set the UI architecture and delivery approach for client-facing React applications.
- Consolidated duplicated pages and components into reusable patterns, making the codebase easier to extend.
- Worked directly with stakeholders to turn business requirements into scoped, production-ready features.
- Diagnosed recurring defects and refactored legacy code to stabilize day-to-day application use.
- Coordinated frontend work with backend and product partners through integration and release.
Featured Projects
Production storefronts, open-source packages, and tools built to solve specific problems.
Replatformed a high-traffic furniture storefront from AEM React to Adobe Edge Delivery Services with Preact. The migration lifted Lighthouse scores from roughly 30 to 90+ and added accessible shopping flows, analytics, and A/B testing.
A control center for Rocket League broadcasts that turns live match data into customizable on-stream overlays. Streamers can switch layouts and tailor the presentation without rebuilding their OBS setup.
A fully functioning Adobe Edge Delivery Services project that uses the EDS backend for authored content and routing while supporting complete local development with npm run dev. Unlike the conventional unbundled EDS architecture, it uses Vite, Preact, and TypeScript to bundle, code-split, and compress block scripts and styles into production-ready assets.
Let's Connect
Have a project in mind or want to discuss an opportunity? I'd love to hear from you.