Senior Full Stack Engineer

HumanSignal is a human data partner for companies building AI models and products. They are seeking a Senior Full-Stack Engineer to build end-to-end features across React/TypeScript and Python/Django, shaping APIs, data models, and background jobs while ensuring UIs are fast, accessible, and trustworthy.

Responsibilities:

• Build full-stack features: React/TypeScript on the client; Django/REST services, data models, and background jobs on the server
• Own outcomes, not tasks: refine scope, suggest trade-offs, propose simpler approaches, and land increments that deliver value fast
• Design clean API contracts and evolve schemas/migrations; improve performance and reliability (query tuning, caching, job orchestration)
• Partner with Product & Design from discovery to delivery: clarify user jobs, write lightweight RFCs/PRDs, and shape scope and milestones
• Keep UIs accessible and responsive; add solid error-handling and failure-mode UX
• Raise engineering standards: testing strategy, code quality, observability hooks, resilience patterns
• Partner with Support to investigate production issues, reduce UX papercuts, and turn learnings into fixes
• 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 full-stack features (React/TypeScript + Python/Django + SQL)
• Strong product sense: you've made scope/trade-off decisions and iterated based on real-world usage and feedback
• Fluency with modern FE tooling (e.g., Vite/Webpack, Jest/Cypress) and state-management patterns
• Backend depth: REST API design, relational modeling, migrations, performance tuning, and background job patterns
• Excellent communication at a Senior IC level—you write clear RFCs/PRDs, give actionable reviews, and present trade-offs well
• GraphQL familiarity; Kafka/queues/streaming; Spark/BigQuery; auth/RBAC; multi-tenant SaaS; design-system experience