Founding Engineer, Full Stack ($160k-$220k + Equity) at River

About the role

River is an early-stage AI startup backed by the founders of Ramp, Kalshi, and JumpCloud, building sophisticated voice AI agents that handle sales calls, answer questions, and perform product demos through browser control. The role is based in New York, USA.

Responsibilities

• Build and scale real-time voice AI infrastructure using TypeScript, Node, and Next.js, ensuring sub-second latency for live sales conversations and automated demos.
• Take full ownership of the production environment, managing everything from feature design and browser automation to deploys, monitoring, and incident response.
• Collaborate directly with founders to influence product direction, making critical architectural decisions and shipping features without waiting for external specs.

Requirements

• 3 to 7 years of hands-on IC experience shipping and running production software used by real people.
• Deep proficiency in TypeScript and Node.

Qualifications

• Track record of building real-world applications with LLM APIs.
• Experience with real-time streaming technologies such as WebRTC, voice, or WebSockets.
• High‑ownership mindset with prior experience at Tier‑1 venture‑backed startups (e.g., Sequoia, a16z) or as a former technical co‑founder.

Skills

• TypeScript
• Node.js
• Next.js
• WebRTC
• Voice processing
• WebSockets

Benefits

• Significant equity stake in an early‑stage AI startup.

Pay

Salary range: $160,000 – $220,000 + equity.