Senior Software Engineer (Backend, 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 monitors vital physiological metrics to offer personalized insights that enhance fitness, health, and recovery. The Growth Team at WHOOP is a fast-paced, experimentation-driven group focused on driving user acquisition, activation, and retention. We take a data-driven approach to everything we do, frequently measuring the performance of our features and iterating based on those results. As a Senior Software Engineer, you will play a key role in building backend services that directly impact our business metrics and accelerate member growth. You'll work cross-functionally to deliver high-leverage features and contribute to system architecture decisions, helping WHOOP scale to millions of members. RESPONSIBILITIES Design and build scalable and reliable backend services to support growth experiments, e-commerce flows, and member engagement initiatives. Collaborate closely with Product, Design, and cross-functional Engineering teams to define and deliver impactful features. Maintain and optimize APIs and infrastructure using Java, Kafka, Postgres, and AWS technologies. Take ownership of end-to-end development, from breaking down requirements to implementation, testing, deployment, and monitoring. Mentor junior engineers and contribute to the growth of engineering best practices across the team. QUALIFICATIONS Professional experience developing large-scale backend systems in a production environment. Deep proficiency in building and maintaining RESTful APIs and working with relational databases (e.g., Postgres). Experience with event-driven architectures and tools like Kafka or SQS. Strong testing practices and clear documentation habits. Ability to thrive in a fast-paced, iterative environment focused on growth and experimentation. Proven collaboration skills across engineering, product, and data teams. A growth mindset and excitement for tackling ambiguous challenges. Bonus: Experience building A/B testing infrastructure or growth-focused engineering features. Learn 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.