Product Engineer, Full-Stack AI

Product Engineer (Full-Stack, AI) New York City (In-office) | Full-Time | Early-Stage Compensation : $150K - $190K About the Company InCommon is hiring on behalf of a US company that builds AI voice agents that serve as full-cycle B2B SaaS sellers, capable of qualifying prospects, answering complex questions, demoing products live in a browser, and following up until deals close — all available 24/7. Founded by serial entrepreneurs who previously sold their first company, River just closed a $2M pre-seed backed by the founders of Ramp, Kalshi, JumpCloud, and other unicorn founders, along with institutional money from Shuruk. The company turned on revenue recently and scaled from $4,000 to $50,000 in weekly revenue within days of launch, with far more demand than they can currently serve. You'd be joining as the first engineering hire outside the founding team, working directly with the founders to ship production software weekly. The Role We're looking for a product-minded full-stack engineer (2–5 years) who has shipped real software and wants to build at the frontier of AI and sales tech. You'll own the backend services powering live AI sales calls, build the browser-use agent that demos real products in real time while the AI talks to prospects, and work directly with our design partners to shape what we build. This is a 0→1 role. You'll move fast, make decisions independently, and see your work go live with real customers every week. What You'll Build Backend services and APIs behind live AI sales calls (session state, integrations, data pipelines)A browser-use agent that navigates and demos real products live during callsLLM-powered workflows — prompts, tool use, and agentic flows the agent follows during demosReal-time systems handling voice, streaming, and live call infrastructureUI in Next.js/React where needed, iterating directly from what you see in real calls What We're Looking For 2–5 years of professional software engineering experience with shipped production softwareStrong TypeScript/JavaScript backend skills (Node.js, Next.js, Postgres)Hands-on experience building with LLMs — agents, tool use, prompt engineeringExperience with real-time systems (WebSockets, WebRTC, streaming) or browser automationBuilt directly with customers or design partners — you understand that engineering and product are the same job at this stageHigh-ownership mindset — you find problems, make decisions, and ship without hand-holdingActive side projects or founder attempts with real users, revenue, or traction are a strong plusBackground in sales tech or GTM tooling is a bonusCS degree from a strong program, or equivalent demonstrated through exceptional shipped work Why River First engineering hire — enormous scope and ownership from day oneWorking directly with founders on a product that's already in-marketCompetitive compensation + meaningful early equityIn-office in NYC with a tight-knit team moving fast Based in NYC or ready to relocate? We'd love to talk.