As a Full-Stack Product Engineer at River, you will build the core infrastructure powering live AI sales interactions. You will develop backend services for session state, engineer sophisticated LLM workflows, and create browser-automation agents for live demos. Joining a small founding team, you will ship to production daily in a high-intensity, in-person New York environment.
Full-Stack Product Engineer at River
River is hiring a Full-Stack Product Engineer in NYC to build the future of autonomous sales. Backed by the founders of Ramp and Kalshi, River is creating AI voice agents that perform live product demos and close deals 24/7. We are looking for a backend-leaning builder who has shipped real software and worked with LLM APIs. If you want to ship to production daily and take massive ownership on a small founding team, this is for you.
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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 the backend services and data pipelines behind live AI calls, managing session state and complex integrations using Node.js and Postgres.
- Engineer LLM-powered workflows using OpenAI and Anthropic APIs to handle sophisticated prompting, tool use, and automated demo flows.
- Develop and maintain the browser-use agent using Playwright to navigate live product environments seamlessly during customer interactions.
Who this is a fit for
- 1-3+ years of experience shipping production-grade software in TypeScript and Node.js with a strong focus on backend architecture and data.
- Proven track record of building and launching real products using LLM APIs, demonstrating an understanding of reliability and performance.
- High-ownership mindset with the ability to thrive in a scrappy, in-office startup culture without the need for detailed specifications.
Why this role is remarkable
- Join a high-velocity founding team backed by elite investors and the founders of category-defining companies like Ramp and Kalshi.
- Work at the frontier of AI by building agents that perform complex, real-time product demonstrations in a live browser environment.
- Experience true product ownership with the autonomy to identify problems, build solutions, and ship features to production on a daily basis.
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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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.