Founding AI Product Engineer

Fluency Digital, Inc.; San Francisco (CA); On-site; USD 180,000 - 260,000; Full time

Job summary

Fluency Digital, Inc. in San Francisco is building a unified OpenAI-format API layer that unifies LLM provider integrations and eliminates bespoke glue code.

You will extend the core SDK and API surface, architect Python backend services with FastAPI, shape the TypeScript interface developers touch, and ship infrastructure to route LLM traffic across AWS and Azure. The role requires 5–7 years of engineering experience, fluency in Python/FastAPI, strong TypeScript skills, and hands-on REST API

Qualifications

• 5–7 years building developer tools, SDKs, or API integrations.
• Fluency in Python and FastAPI; strong TypeScript skills.
• Experience wiring REST APIs to cloud infrastructure (AWS/Azure).
• On-site in San Francisco; based in the United States.

Responsibilities

• Extend core SDK and API surface to standardize provider integrations.
• Architect backend systems in Python/FastAPI; shape TypeScript interfaces.
• Ship enterprise-ready infrastructure to route LLM traffic across AWS and Azure.
• Collaborate with a tight, focused team on-site in SF.

Skills

Python

FastAPI

TypeScript

REST APIs

Tools

AWS

Azure

Git

OpenAI

Job description

Building a unified OpenAI-format API layer for every major LLM provider.

Every new language model brings a fractured integration pattern, forcing developers to write bespoke glue code just to swap between Anthropic, Llama, and Huggingface. As a founding product engineer, you will collapse that fragmentation by extending the core SDK and API surface that translates any provider into a single, reliable standard. You will architect backend systems in Python and FastAPI, shape the TypeScript interface developers actually touch, and ship the infrastructure that enterprise teams depend on to route LLM traffic across AWS and Azure.

What we’re looking for

• 5 to 7 years of engineering experience building developer tools, SDKs, or complex API integrations.
• Deep fluency in Python and FastAPI for backend services, plus competency in TypeScript.
• Proven experience wiring REST APIs to cloud infrastructure on AWS or Azure.
• Strong bias toward shipping functional code over theorizing about architecture in an early-stage environment.
• Comfortable working on‑site in San Francisco alongside a tight, focused team.
• Must be based in the United States.

Tech stack

Python, FastAPI, TypeScript, OpenAI, AWS, Azure, REST API, Git