Senior Backend Engineer

About the Role

Join HumanSignal to design and operate scalable backend services that power cutting-edge AI data labeling and evaluation workflows, shaping the future of AI development.

Responsibilities

• Design, build, and operate backend services and APIs using Python/Django with Postgres/Redis.
• Own project outcomes by refining scope, suggesting trade-offs, and delivering value incrementally.
• Model data, author migrations, tune queries, manage background jobs, and optimize performance for high-volume workflows.
• Evolve API contracts with the frontend team, ensuring clear, versioned, and resilient interfaces.
• Implement secure, multi-tenant patterns including authentication, RBAC, auditability, and data isolation.
• Contribute to testing strategies, error handling, and graceful failure modes.
• Engage with the open-source community to understand user needs and improve developer experience.
• Participate in architecture discussions, code reviews, and mentor teammates.

Requirements

• Senior-level experience shipping production backends in Python/Django and SQL.
• Strong product sense with experience making scope and trade-off decisions based on user feedback.
• Deep understanding of REST API design, relational modeling, migrations, and performance tuning.
• Experience with background processing/queues (e.g., Celery, RQ) and operational concerns.
• Clear written communication skills for RFCs, PRDs, reviews, and decision records.

Nice-to-Haves

• GraphQL familiarity.
• Experience with Kafka/streaming technologies.
• Familiarity with Spark/BigQuery.
• Exposure to security/compliance requirements.
• Experience with multi-region architectures.