Senior Software Engineer (Backend, Core & Ecosystem)

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.

As a Senior Software Engineer (Backend) focusing on Core & Ecosystem, you will play a critical role in building and scaling the foundational systems that power the WHOOP member experience for sleep, strain, and recovery. Additionally, the work you do will support the WHOOP connected member experience for new and existing partnerships, external developer apps, and supporting platform. This team is responsible for developing the infrastructure and shared services that enable data pipelines, algorithms, and scalability across the product. You will collaborate closely with product management, design, data science, and fellow engineers to architect and deliver reliable, high-impact backend systems that support member-facing features. You will lead technical planning for complex initiatives, mentor other engineers, and raise the bar for engineering excellence across the backend.

RESPONSIBILITIES:

● Lead the design and implementation of core backend capabilities (for example new data pipelines, improved scalable and resilient architectures) 

● Drive technical planning for initiatives, including scoping and sequencing work, identifying dependencies and risks, and communicating tradeoffs and timelines to stakeholders 

● Deliver high-quality, member-facing features, collaborating with cross-functional partners to ensure requirements are met and outcomes are measurable 

● Maintain and improve system performance, scalability, and reliability across APIs and infrastructure using Java, Kafka, Postgres, and AWS technologies 

● Establish and evolve shared engineering standards through code reviews, documentation, and architectural discussions, influencing patterns used across backend development

● Mentor and support other engineers through pairing, feedback, and knowledge sharing, helping grow individual capability and the overall health of the codebase

QUALIFICATIONS:

● Significant experience building and operating large-scale backend systems in a production environment 

● Deep expertise in API design and development, including RESTful services and relational databases such as Postgres 

● Experience working with event-driven or asynchronous systems such as Kafka or SQS 

● Proven ability to design systems for scalability, reliability, and performance 

● Experience writing well-tested, maintainable code with clear documentation 

● Strong collaboration and communication skills, with experience working cross-functionally 

● Growth mindset with a desire to learn, iterate, and improve in a complex and evolving environment 

● Bonus: Experience working full-stack (for example, Swift or Kotlin), or building shared services used across multiple product areas