As the first engineering hire at River, you will build AI voice agents that autonomously drive browsers and conduct real-time sales calls. Working directly with founders and design partners, you’ll own the full-stack experience from the live call interface to complex LLM integrations, iterating weekly based on real-world performance.
Founding Product Engineer at River
River is redefining B2B sales with AI voice agents that actually drive browsers and conduct live product demos. Backed by the founders of Ramp, Kalshi, and JumpCloud, this NYC-based startup is looking for its first engineering hire. As a Founding Product Engineer, you'll work directly with the founders to build a production-grade AI platform that is already seeing significant revenue and customer demand. If you are a TypeScript expert with 2-4 years of experience and a passion for shipping LLM-powered products that real people use, this is a rare opportunity to join an elite team at the pre-seed stage and shape the future of autonomous sales.
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Location
New York, United States
Compensation
$150k-$190k + 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
- Lead full-stack development with a focus on the live call experience, agent-driven demos, and the core dashboard surfaces used by enterprise design partners.
- Partner directly with customers to learn their specific sales motions, then rapidly build, deploy, and monitor the agents during live production calls.
- Engineer robust systems around LLM APIs to ensure high reliability and low latency, moving beyond prototypes to production-grade software that handles mission-critical sales interactions.
Who this is a fit for
- Holds 2–4 years of professional experience as an IC, with a deep mastery of TypeScript and Node.js used to ship and maintain software with real users.
- Possesses hands-on experience with LLM APIs and can clearly articulate the challenges and solutions required to make generative model outputs reliable for production use.
- Demonstrates a true builder’s pedigree, evidenced by a history of launching side projects with traction, founding a startup, or shipping 0–1 products at high-bar companies.
Why this role is remarkable
- Join as the first hire alongside two founders, directly shaping the technical foundation and product direction of a high-growth AI company where demand already outpaces capacity.
- Benefit from a powerhouse cap table featuring the founders of Ramp, Kalshi, and JumpCloud, providing both world-class mentorship and a strong signal of market fit.
- Solve complex, real-time engineering challenges involving voice AI, WebRTC, and browser automation to build a product that generates immediate revenue and tangible customer value.
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.