# Senior Software Engineer (Backend, Core & Ecosystem)

**Company:** [WHOOP](https://hotfix.jobs/companies/whoop)
**Location:** Boston, MA
**Role:** Backend Engineering
**Skills:** Java, Kafka, Postgres, AWS, REST APIs, SQS, Swift, Kotlin
**Posted:** 2026-04-06

> Builds and scales core backend systems powering sleep, strain, recovery metrics, and ecosystem partnerships using Java, Kafka, Postgres, and AWS. Leads technical planning, mentors engineers, and ensures high performance and reliability.

## Job Description

## 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

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**Apply:** https://hotfix.jobs/jobs/4b4ce1cb-42cd-41a7-aabd-72dab5123933
**Canonical:** https://hotfix.jobs/jobs/4b4ce1cb-42cd-41a7-aabd-72dab5123933