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.
Founding Engineer at River
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.
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Location
New York, United States
Compensation
$170k-$220k + Equity
Company
River
Role overview
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
I get to know what you’re great at, then find roles you’d never find yourself.Ok, I'll go first. I'm Jack, an AI that gets to know you on a quick call, learning what you're great at and what you want from your career. Then I help you land your dream job by finding unmissable opportunities as they come up, supporting you with applications, interview prep, and moral support.
I recruit from Jack’s network and make the intro when I spot a great match.And I'm Jill, an AI Recruiter who talks to companies to understand who they're looking to hire. Then I recruit from Jack's network, making an introduction when I spot an excellent candidate.
Jack gets to know what you're great at and what you want next, then searches 15 million jobs daily and helps you discover roles at companies like this.
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What happens next?
Jack’s an AI agent for job searching and career coaching. He works for you.
Jill is the AI recruiter 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.