All vacancies
HumanSignal

Senior Backend Engineer

HumanSignal · remote · senior · full-time · $115000–$195500 USD
aidevtech PythonDjangoPostgresRedisJSTSReactOpenAI APISparkBigQueryKafkaJest
8.7
AI Score
The vacancy is well-structured and informative, providing clarity on responsibilities and expectations.
Job description
At HumanSignal, we’re building the platform that powers the creation, curation, and evaluation of high-quality data for AI. Our open-source product, Label Studio, is widely adopted for labeling and evaluating data across various modalities. We focus on ensuring models are grounded in real-world signals.
Responsibilities
- Design, build, and operate backend services/APIs in Python/Django with Postgres/Redis. - Own outcomes, not tasks: refine scope, suggest trade-offs, and land increments that deliver value quickly and safely. - Model data and author migrations; tune queries and caching; manage background jobs/queues for high-volume workflows. - Evolve API contracts with FE; keep interfaces clear, versioned, and resilient to change. - Improve reliability and performance (timeouts, retries, idempotency, rate limits, pagination, backpressure). - Implement secure, multi-tenant patterns: auth, permissions/RBAC, auditability, and safe data boundaries. - Contribute to testing strategy (unit/integration), error handling, and graceful failure modes. - Partner with Support to investigate production issues and turn learnings into fixes and prevention. - Engage with our open-source community (issues, discussions) to understand real-world needs and improve developer experience. - Participate in architecture discussions and code reviews; mentor teammates and improve patterns across the codebase.
Requirements
- Senior-level experience shipping production backends in Python/Django (or a close equivalent) and SQL. - Strong product sense: you’ve made scope/trade-off decisions and iterated based on real-world usage and feedback. - Depth in REST API design, relational modeling, migrations, and performance tuning. - Experience with background processing/queues (e.g., Celery/RQ/Kafka-backed workers) and operational concerns. - Clear written communication at a Senior IC level—concise RFCs/PRDs, actionable reviews, and crisp decision records. - Nice to have: GraphQL familiarity; Kafka/streaming; Spark/BigQuery; security/compliance exposure; multi-region architectures.
About HumanSignal
HumanSignal is a software company that provides data labeling, evaluation, and quality workflows for AI and machine learning teams. It is best known for Label Studio, an open-source platform used to prepare training data, fine-tune models, and support human-in-the-loop AI workflows. In 2025, it expanded into multimodal data services and expert annotation through HumanSignal Services.
AI · 51-200 · San Francisco, California, USA · Founded 2019 · https://humansignal.com
Apply to this role