Senior Frontend Engineer I - eCommerce

About this role

About Us
At Prenuvo, we are on a mission to flip the paradigm from reactive “sick-care” to proactive health care. Our award-winning whole body scan is fast (under 1 hour), safe (MRI has no ionizing radiation), and non-invasive (no contrast). Our unique integrated stack of optimized hardware, software, and increasingly AI, coupled with the patient-centric experience across our domestic and global clinics, have allowed us to lead the change against “we caught it too late again".
We're looking for a Senior Frontend Engineer I to join our eCommerce team, building the online booking experience patients use to choose a scan, find a clinic, pay, and schedule their appointment. You'll lead complex features in a Next.js and TypeScript application that serves customers in multiple countries, on flows where every screen directly affects conversion, revenue, and patient trust: product selection, checkout and payments, appointment scheduling across timezones, and our sales-assisted and partner booking paths. This is a high-impact role for someone who cares about the craft of the UI and about whether it actually works in production for every customer. If you enjoy solving ambiguous problems and owning outcomes rather than tickets, we'd love to hear from you.
This role does not provide visa sponsorship. Applicants must be legally authorized to work in the United States at the time of hire and must not require employer sponsorship for a work visa (current or future).
Help reshape the world through proactive healthcare while working with cutting-edge technology and high performing teams with deep expertise - join us to make a difference in people’s lives!
What You’ll Do

• Own features and components within an area of the booking experience, such as checkout and payments, scheduling, or the sales-assisted and partner flows, growing toward owning the area end to end.

• Work with Product and Marketing on growth: ship experiments on the booking funnel, then read the results honestly, including sample size, guardrail metrics, and whether a change is a real win or just noise.

• Build fast, accessible, customer-facing features with React, Next.js (App Router), and TypeScript.

• Contribute to frontend architecture and design, writing proposals you review with senior engineers: sensible server and client component boundaries, server state with TanStack Query, client state with Zustand, and type-safe forms with React Hook Form and Zod.

• Integrate the booking experience with our commerce APIs and third-party services, including Stripe, Affirm, commercetools, Voucherify, Salesforce, Auth0, and Google Maps.

• Instrument what you ship: Datadog RUM for errors and performance, PostHog for product analytics, feature flags, and experiments, and Google Tag Manager for marketing measurement, all respecting each customer's consent choices.

• Improve Core Web Vitals, bundle size, and rendering performance on a high-traffic, revenue-critical funnel.

• Make accessibility a default: semantic markup, keyboard and screen reader support, and automated accessibility checks in CI.

• Write automated tests at the right level: Vitest and Testing Library for components, MSW for API mocking, and Playwright for end-to-end booking flows.

• Own outcomes in production: ship behind feature flags, watch the dashboards after release, and follow through when something breaks. You are accountable for whether a feature works for customers, not just whether it merged.

• Partner closely with Product, Design, Marketing, and Backend engineers, contributing to our shared component library and agreeing the API contracts the frontend depends on.

• Provide technical guidance through design discussions and high-quality code review, and mentor junior engineers.

• Use AI-assisted development tools thoughtfully as part of a structured build, review, and test workflow.

What You’ll Bring

• Typically 4+ years of professional frontend engineering experience, including at least 3 years building production applications with React and TypeScript.

• Strong experience with Next.js or a comparable React framework, including server-side rendering, routing, and the tradeoffs between server and client rendering.

• Deep understanding of browser fundamentals: semantic HTML, modern CSS and responsive layout, the event loop, network and caching behavior, and the rendering pipeline.

• Experience with modern data-fetching and state management patterns (TanStack Query, Zustand, Redux, or similar) and with complex, validated, multi-step forms.

• Strong testing practices across unit, component, and end-to-end layers, using tools such as Vitest or Jest, Testing Library, and Playwright or Cypress.

• Experience building checkout, payment, or other transactional flows where correctness and reliability matter.

• Working knowledge of web accessibility (WCAG 2.1 AA) and web performance (Core Web Vitals).

• Experience with frontend observability and product analytics tools such as Datadog RUM, Sentry, PostHog, or Google Analytics.

• Hands-on experience with modern CI/CD practices and cloud hosting (for example GitHub Actions and AWS).

• A track record of leading complex features from design through production.

• A startup mindset: comfortable taking on ambiguous work, knowing when to pull in a second opinion on an approach, and able to balance speed with quality.

• Excellent communication skills and the ability to collaborate across engineering, design, and business teams.

Nice to Have

• Experience with Stripe.js and payment method integrations, including buy now, pay later providers such as Affirm.

• Experience with headless commerce platforms such as commercetools, or promotion engines such as Voucherify.

• Experience with Tailwind CSS and building on top of a design system or component library.

• Experience with consent management platforms (such as OneTrust), Google Tag Manager, and privacy-aware analytics.

• Experience with multi-region products:…