Founding Full-Stack Engineer San Francisco onsite

Founding Full-Stack Engineer

San Francisco US Citizens Only Onsite

Our client is building the end-to-end testing platform for voice text AI. Backed by Y Combinator Floodgate and top angels they are already working with Fortune 500s and the hottest voice AI startups in Silicon Valley. With $4M in funding and a small but world-class team they are growing fast and looking for thier first Founding Engineer to help shape the future of conversational AI.

What Youll Do

As a founding engineer youll be a full-stack builder and problem-solver:

• Architect and scale systems that simulate analyze and evaluate conversational AI agents (voice multimodal).
• Design resilient AWS infrastructure (Lambda EC2 Websockets SIP) to handle thousands of real-time conversations.
• Develop algorithms and pipelines that surface insights detect failure modes and keep AI safe reliable and aligned with human intent.
• Work directly with customers to deploy test and refine the product in real-world settings.
• Own features end-to-end from conception to deployment ensuring clean maintainable code and scalable systems.

Tech Stack

Python React TypeScript FastAPI Tailwind PostgreSQL Redis Supabase AWS Websockets CI/CD
Voice AI tools: LiveKit Deepgram Cartesia ElevenLabs Gemini Pydantic AI OpenAI

What Were Looking For

• 1 years of experience as a full-stack or founding engineer at an early-stage recognised Invested startup
• Strong experience with Python React PostgreSQL and AWS.
• Bonus: exposure to voice AI technologies (LiveKit Deepgram ElevenLabs Cartesia Gemini).
• Previous role at a high-bar engineering company (e.g. Meta Google Microsoft) or a fast-growth startup (YC top VCs).
• CS degree or equivalent practical experience.
• Excited to work onsite in San Francisco with a small close-knit team.
• Creative hobbies (e.g. YouTube design art) are a plus we love builders with imagination.

Why Join

Youll learn more in a month than years at Big Tech. As a founding engineer youll:

• Have real decision-making power over architecture product and direction.
• Work directly with Fortune 500 clients and fast-growing startups.
• Build with cutting-edge AI tools and ship fast.
• Join an incredibly close-knit team at our HQ The Nest.

About our client

Founded by ex-Microsoft and AWS engineers they graduated from YC X25 and grew to $100K ARR in just two weeks. Trusted by some of the worlds largest enterprises they are quickly becoming the gold standard for testing conversational AI.

Apply now to get in with this exciting career opportunity or DM to find out more