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Job description
Job Title
Founding Engineer, Full Stack (Backend)
Salary
$160k-$220k + Equity
Company Description
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.
Job Description
Join River as our first engineering hire to build high-performance voice AI agents. You will work directly with the founders in our New York office, owning significant parts of our real-time infrastructure and product features. This role is perfect for a backend-leaning full-stack engineer ready to define the architecture of a Tier-1-backed startup.
Location
New York, USA
Why this role is remarkable
Work as the first engineering hire alongside founders backed by industry leaders from Ramp, Kalshi, and JumpCloud, enjoying significant equity and direct product influence.
Solve complex, sub-second latency challenges in real-time voice AI and browser automation that go far beyond simple LLM wrappers or basic tutorials.
Join a high-velocity, in-office culture in New York that prioritizes extreme ownership, shipping fast, and building AI-native tools that multiply individual output.
What You Will Do
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.
The ideal candidate
Has 3 to 7 years of hands-on IC experience shipping and running production software used by real people, with deep proficiency in TypeScript and Node.
Possesses a track record of building real-world applications with LLM APIs and has experience with real-time streaming technologies like WebRTC, voice, or WebSockets.
Demonstrates a high-ownership mindset with previous experience at Tier-1 venture-backed startups (e.g., Sequoia, a16z) or as a former technical co-founder.
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Worksite address
new york, NY, 10261, US
Who can apply
Review the original listing for work authorization, qualifications and employer requirements.