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Founding Engineer at River
- Location
- New York, United States
- Compensation
- $170k-$220k + Equity
River is redefining B2B sales with AI voice agents that demo products in real-time, and we’re looking for a Founding Engineer to lead this technical frontier in NYC. Backed by the founders of Ramp and Kalshi, our second-time founders have built a sub-second loop involving WebRTC, avatars, and LLMs that is already generating compounding revenue.
You will own the live-call pipeline and infrastructure while earning significant founding equity up to 2.5%. If you are a high-ownership builder with deep streaming expertise and founder DNA who wants to define a company's technical soul, this is your seat.
What's the next step?
This role is no longer actively hiring, but Jack can still help you discover similar open roles that fit.
Role overview
As a Founding Engineer at River, you will lead the development of real-time AI agents that handle live sales calls. You’ll own the entire pipeline—from WebRTC streaming to browser-use agents—while building the company’s engineering foundations. This is a high-ownership role for a technical entrepreneur ready to define a new category.
About River
AI Sales
River builds AI voice agents that sell. Backed the founders of Ramp and Kalshi.
What you will do
- Architect and own the live-call pipeline, integrating real-time voice, video avatars, and browser streaming into a sub-second loop.
- Build and scale critical infrastructure, including deploys, observability, and cost-optimization for high-concurrency production environments.
- Establish core engineering foundations, including monitoring and testing frameworks, while shipping high-impact features across the full stack.
Who this is a fit for
- 5+ years of experience building production backend systems with a founder-grade track record as an ex-CTO, co-founder, or early breakout employee.
- Deep technical expertise in real-time streaming technologies such as WebRTC, WebSockets, or low-latency media servers.
- Degree from a tier-1 university and a high-ownership temperament, comfortable navigating the ambiguity of an early-stage, fast-moving environment.
Why this role is remarkable
- True founding seat with meaningful equity (up to 2.5%) and direct influence over the product roadmap alongside experienced second-time founders.
- Elite backing from industry titans including the founders of Ramp, Kalshi, and JumpCloud, plus investment from Shorooq.
- Work on frontier technical challenges like sub-second latency voice, avatar rendering, and reliable autonomous browser-use agents in production.
How Jack & Jill work together
What happens next?
Jack’s an AI agent for job searching and career coaching. He works for you.
Jill is the AI agent for hiring, working for the company. She recruits from Jack’s network.
If your profile’s a match and River wants to meet, Jill will make the intro. In the meantime, Jack will send you excellent alternatives.