Backend Engineer II: Scalable APIs & Growth Tech

WHOOP; Boston (MA); On-site; USD 140,000 - 210,000; Full time

Job summary

WHOOP in Boston is seeking a professional backend engineer to build scalable services and APIs supporting our membership growth experiments. You will collaborate with product managers, designers, and engineers to deliver reliable, high-availability systems using Java, Kafka, Postgres, and AWS.

You will write tests, review code, and help shape backend architecture. Experience in production environments and strong communication with non-technical stakeholders is valued; growth mindset and

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.

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.

Skills

Backend engineering

API design

Cross-functional collaboration

Testing & documentation

Communication

Growth mindset

A/B testing

Tools

Kafka

Postgres

AWS

SQS

Job description

WHOOP in Boston is seeking a professional backend engineer to build scalable services and APIs supporting our membership growth experiments. You will collaborate with product managers, designers, and engineers to deliver reliable, high-availability systems using Java, Kafka, Postgres, and AWS.

You will write tests, review code, and help shape backend architecture. Experience in production environments and strong communication with non-technical stakeholders is valued; growth mindset and