AI devtools startup building LLM API abstraction layer

Senior Backend Engineer

San FranciscoOn-site$200K - $260K3+ years
We're building infrastructure that standardizes how developers interact with multiple large language models through a unified API interface. You'll work on a backend system that routes requests across different LLM providers, handling billions of API calls reliably and efficiently. This is a backend-focused role on a small, focused team in San Francisco working on problems at the intersection of AI and developer tools.

What we're looking for

  • 3+ years backend engineering experience with Python or Rust
  • Production experience building and scaling API services, ideally with FastAPI or similar frameworks
  • Experience with PostgreSQL, Redis, and observability tools like Prometheus
  • Strong systems design skills for high-volume, low-latency request routing and caching
  • Ability to work on-site in San Francisco

Tech stack

PythonRustFastAPIPrometheusPostgreSQLRedis

Apply for this role

This role is one we're recruiting for on behalf of a client company; the client's identity is kept confidential at this stage. A Fluency recruiter will follow up with details.