River is a $2M pre-seed startup backed by the founders of Ramp and Kalshi building AI voice agents for B2B sales. As a Product Engineer, you will build real-time services, LLM workflows, and browser-automation agents. Working directly with founders in New York, you’ll ship daily to production for our first customers.
Product Engineer (Full-Stack) at River
River is building the future of sales with AI voice agents that qualify prospects and demo products by controlling browsers live. Backed by the founders of Ramp, Kalshi, and JumpCloud, this $2M pre-seed startup is looking for a Product Engineer to join their high-intensity NYC office. You will work directly with the founders to build real-time services, LLM-powered workflows, and browser-use agents that ship to production daily. If you are a scrappy developer with strong TypeScript skills and a passion for building software that real people use, this is a unique opportunity to secure founding-level equity and massive impact.
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Location
New York, United States
Compensation
$90k-$140k + Equity
Company
River
Role overview
AI Sales
River deploys AI voice sales agents in B2B companies. Backed by the founders of Ramp and Kalshi.
What you will do
- Build and optimize the backend services behind live voice calls, including session state management, integrations, and data pipelines.
- Develop and refine the browser-use agent that performs live product demos and the automated prospect enrichment pipeline.
- Architect and implement LLM-powered workflows to handle complex sales qualification and real-time prospect interactions.
Who this is a fit for
- 1-3+ years of experience shipping production-grade software in TypeScript/Node, with a strong focus on backend systems and APIs.
- Proven track record of building functional applications using LLM APIs and a solid comfort level working across the React stack.
- Currently based in New York and thrives in a high-intensity, in-person office culture with a builder’s mindset.
Why this role is remarkable
- Work at the bleeding edge of AI, building agents that don’t just talk but navigate software live via browser automation.
- High-velocity environment with direct founder collaboration, shipping code to production almost every single day to serve active customers.
- Backed by elite founders from Ramp, Kalshi, and JumpCloud, offering significant equity and a trajectory-focused career path.
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.