Product Engineer (Full-Stack) ($90k-$140k + Equity) at River

About the role

River is a $2M pre-seed startup backed by the founders of Ramp, Kalshi, and JumpCloud building AI voice agents for B2B sales. Their technology conducts real-time qualification calls, demos products by live-controlling browsers, and manages automated follow-ups to close deals for sales teams.

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.

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.

Qualifications

• 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.

Pay

$90k-$140k + Equity

Location

New York, USA