Software Engineer II (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.The Growth team is responsible for accelerating member acquisition, activation, engagement, and retention through rapid experimentation and thoughtful product development. As a Software Engineer II (Backend), you’ll contribute directly to building and optimizing backend systems that power WHOOP’s growth initiatives. You’ll deliver high-impact features that directly influence member and business outcomes. You’ll work closely with Product, Design, and fellow engineers in a fast-paced, experiment-driven environment where iteration, measurement, and continuous improvement are core to how we build.RESPONSIBILITIES:Collaborate closely with product managers, designers, and fellow engineers to develop scalable and reliable backend services.Build, maintain, and optimize APIs and infrastructure supporting our acquisition funnels, e-commerce experiences, and membership growth experiments.Write well-tested, maintainable code using technologies such as Java, Kafka, Postgres, and AWS.Break down feature requirements into actionable tasks, prioritize work, and consistently deliver on sprint commitments.Contribute to backend architecture discussions and implementation of scalable, high-availability services that support millions of users.Work with data scientists and analytics engineers to support experimentation and measure performance.Participate in code reviews and collaborate on best practices with your engineering peers.QUALIFICATIONS:Professional backend engineering experience in a production environment.Proficiency in building APIs and working with relational databases (e.g., RESTful APIs, Postgres).Experience with event-driven systems and asynchronous processing tools such as Kafka or SQS.Skilled in writing comprehensive tests and clear documentation.Demonstrated ability to work cross-functionally and communicate clearly with technical and non-technical stakeholders.A growth mindset and eagerness to learn from feedback and new challenges.Bonus: Experience with A/B testing frameworks or growth-focused engineering initiatives.