Senior Software Engineer (Frontend, Growth)

At WHOOP, we're on a mission to unlock human performance and healthspan. WHOOP empowers members to perform at a higher level through a deeper understanding of their bodies and daily lives. Our wearable technology and digital experiences translate complex physiological data into clear, personalized insights that help members improve their fitness, health, and recovery.The Growth Team at WHOOP is a fast-paced, experimentation-driven group focused on driving user acquisition, activation, engagement, and retention. As a Senior Software Engineer on the Growth team, you will own and drive the technical direction of our web experiences, including our join flow, checkout, and shop that directly impact conversion, revenue, and member engagement. You will lead cross-functional initiatives from technical planning through rollout, mentor engineers across the team, and shape the architecture and practices that allow Growth to move quickly and confidently at scale.RESPONSIBILITES:Own the architecture and technical direction of WHOOP's web experiences, including our Next.js-based join flow, Cloudflare Workers edge infrastructure, and Stripe-powered checkoutLead cross-functional projects end-to-end from brainstorm and technical planning through implementation, QA, rollout, and post-launch analysis, partnering closely with Product, Design, and AnalyticsDesign and execute experiments (A/B tests) with rigor, ensuring proper instrumentation, measurement, and iteration based on impact to North Star metricsDrive frontend performance, accessibility, and reliability across devices and browsers, establishing standards and monitoring that the team can build onWrite clean, well-tested, production-quality code in TypeScript/React/Next.js and integrate deeply with backend services, payment systems (Stripe), and ecommerce platforms (CommerceTools)Author and review technical plans, identify architectural tradeoffs, and make sound judgment calls that balance speed with long-term maintainabilityMentor and develop other engineers through code review, pairing, and technical guidance, raising the bar for quality and velocity across the web surfaceParticipate in on-call rotations and incident response; lead postmortems and drive improvements that prevent recurrenceContribute to Growth's engineering culture through documentation, process improvements, and knowledge sharingQUALIFICATIONS:5+ years of professional experience in frontend software engineering, with deep expertise inTypeScript, React, and modern web frameworks (Next.js strongly preferred)Track record of owning and delivering complex, cross-functional web projects from technical design through production rolloutStrong understanding of web performance optimization, edge computing (e.g., Cloudflare Workers), and responsive design at scaleExperience integrating frontend applications with payment systems (Stripe preferred), RESTful APIs, and third-party platformsDemonstrated ability to design and run meaningful A/B tests and make data-informed decisions in a growth or product engineering contextExperience with observability and monitoring tools (e.g., Datadog, Sentry, Amplitude) to proactively identify and resolve production issuesProven ability to mentor engineers, lead technical discussions, and influence engineering practices across a teamExcellent written and verbal communication skills; comfortable operating in an async-first, cross-functional environmentBonus: Experience with ecommerce platforms (CommerceTools), feature flag / experimentation infrastructure, or subscription/membership business modelsLearn more about our Software Org and how to be successful in your engineering career at WHOOP via our Career Framework.This role is based in the WHOOP office located in Boston, MA. The successful candidate must be prepared to relocate if necessary to work out of the Boston, MA office.Interested in the role, but don’t meet every qualification? We encourage you to still apply! At WHOOP, we believe there is much more to a candidate than what is written on paper, and we value character as much as experience. As we continue to build a diverse and inclusive environment, we encourage anyone who is interested in this role to apply.WHOOP is an Equal Opportunity Employer and participates in E-verify to determine employment eligibility. It is unlawful in Massachusetts to require or administer a lie detector test as a condition of employment or continued employment. An employer who violates this law shall be subject to criminal penalties and civil liability.The WHOOP compensation philosophy is designed to attract, motivate, and retain exceptional talent by offering competitive base salaries, meaningful equity, and consistent pay practices that reflect our mission and core values.At WHOOP, we view total compensation as the combination of base salary, equity, and benefits, with equity serving as a key differentiator that aligns our employees with the long-term success of the company and allows every member of our corporate team to own part of WHOOP and share in the company’s long-term growth and success.The U.S. base salary range for this full-time position is $150,000 - $215,000. Salary ranges are determined by role, level, and location. Within each range, individual pay is based on factors such as job-related skills, experience, performance, and relevant education or training. In addition to the base salary, the successful candidate will also receive benefits and a generous equity package.These ranges may be modified in the future to reflect evolving market conditions and organizational needs. While most offers will typically fall toward the starting point of the range, total compensation will depend on the candidate’s specific qualifications, expertise, and alignment with the role’s requirements.