Senior Frontend Engineer I - eCommerce

Accountabilities: Own key features and components across the eCommerce booking experience, including checkout, payments, appointment scheduling, sales-assisted booking, and partner booking flows. Build fast, accessible, responsive customer-facing experiences using React, Next.js App Router, and TypeScript. Collaborate with Product and Marketing teams to design, launch, and evaluate booking-funnel experiments, interpreting results carefully and distinguishing meaningful improvements from statistical noise. Contribute to frontend architecture decisions, including server and client component boundaries, data-fetching patterns, state management, and type-safe form validation. Integrate the booking platform with commerce APIs and third-party services such as Stripe, Affirm, commercetools, Voucherify, Salesforce, Auth0, and Google Maps. Instrument features with observability and analytics tools, including Datadog RUM, PostHog, and Google Tag Manager, while respecting customer consent and privacy preferences. Improve Core Web Vitals, rendering performance, and bundle size to optimize a high-traffic, revenue-critical customer journey. Make accessibility a core part of development through semantic markup, keyboard navigation, screen-reader support, and automated accessibility checks. Develop and maintain automated tests across component, integration, and end-to-end levels using tools such as Vitest, Testing Library, MSW, and Playwright. Take ownership of production outcomes by releasing features behind feature flags, monitoring performance and errors, and resolving issues after launch. Work closely with Product, Design, Marketing, and Backend Engineering to align requirements, define API contracts, and improve shared components. Contribute to technical discussions and code reviews, provide guidance to colleagues, and mentor junior engineers. Use AI-assisted development tools thoughtfully within structured workflows for implementation, review, and testing. Requirements Typically 4 or more 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 routing, server-side rendering, and the tradeoffs between server and client rendering. Solid understanding of browser fundamentals, including semantic HTML, modern CSS, responsive layouts, the JavaScript event loop, networking, caching, and browser rendering. Experience with modern data-fetching and state-management approaches such as TanStack Query, Zustand, Redux, or equivalent tools. Experience building complex, validated, multi-step forms and transactional user journeys. Strong testing practices across unit, component, and end-to-end testing, using tools such as Vitest or Jest, Testing Library, and Playwright or Cypress. Experience developing checkout, payment, or other transactional flows where accuracy, security, and reliability are essential. Working knowledge of WCAG 2.1 AA accessibility standards and web performance optimization, including Core Web Vitals. Familiarity with frontend monitoring and product analytics tools such as Datadog RUM, Sentry, PostHog, or Google Analytics. Hands-on experience with modern CI/CD practices and cloud-hosting environments, such as GitHub Actions and AWS. Demonstrated ability to lead complex features from initial design through implementation, deployment, and ongoing production support. A proactive, adaptable mindset, with the ability to navigate ambiguity, seek input when needed, and balance delivery speed with engineering quality. Excellent communication and collaboration skills across engineering, design, product, and business teams. Additional experience that is a plus: Stripe.js and payment integrations, including buy-now-pay-later providers such as Affirm; headless commerce platforms such as commercetools; promotion engines such as Voucherify; Tailwind CSS; and design systems or component libraries. Other valuable experience: Consent management platforms such as OneTrust, privacy-conscious analytics, international products involving multiple currencies and locales, and accurate date and timezone handling. Growth and marketing experience is beneficial: Funnel optimization, rapid experimentation, acquisition and conversion metrics, event tracking, UTM and referral attribution, advertising conversion tracking, landing pages, email capture, referral programs, promotional codes, and abandoned-cart recovery. Familiarity with identity providers such as Auth0, scheduling or booking platforms, consumer healthcare applications, or highly regulated industries is an advantage. 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 now or in the future. Benefits Base salary: $145,000–$170,000 in local currency, depending on experience and geographic location. Healthcare coverage: Comprehensive medical, dental, and vision benefits, including mental health coverage, to support employees and their families. Complimentary whole-body scans: Free whole-body scans for team members, supporting a proactive approach to personal health. Retirement savings: Access to a 401(k) plan for eligible employees, with pre-tax contributions. Employer matching contributions are not currently offered. Flexible time off: Flexible vacation policy, with encouragement to take time away to rest and recharge. Commuter benefits: Support for eligible transit and parking expenses through a commuter benefits plan. Professional growth: Opportunities to develop skills, take on new challenges, and shape an individual career path. Collaborative culture: Weekly team gatherings to connect, share ideas, and build relationships. Mission-driven work: The opportunity to contribute to technology designed to advance proactive healthcare and positively affect people's lives.