River builds voice AI agents for B2B comapnies. Our agent talks with prospects in real time, answers hard questions, and demos the product by actually controlling a browser while it speaks. Every call runs on a sub-second loop: speech, a rendered avatar, several LLMs, and a live browser-use agent, in front of real buyers. $2M pre-seed backed by founders of Ramp, Kalshi, and JumpCloud.
Hiring two roles:
Founding Engineer (5+ yrs): own the live-call pipeline (real-time voice, avatar, browser streaming) and the infra behind it. Looking for strong backend/infra plus real-time experience (WebRTC, voice/video, websockets). Stack: TypeScript, Node, Next.js, Postgres, Redis, LiveKit.
Product Engineer, full-stack (1-3 yrs or exceptional projects): build the services behind live calls, LLM workflows, and the browser-use agent that runs demos. Backend-leaning, TypeScript.
Both on-site in NYC, working directly with the founders. Try the product yourself at rivergtm.com/start

Founding Engineer + Product Engineer