Product Engineer

River builds AI voice agents for B2B SaaS sales teams, enabling real-time prospect qualification, product demonstrations, and follow-up. The Product Engineer will build backend services, APIs, LLM-powered workflows, browser-use agents, enrichment pipelines, and supporting UI while collaborating directly with founders and design partners.

Responsibilities:

• Build the backend services and APIs behind live calls: session state, integrations, data pipelines
• Build the LLM-powered workflows: prompts, tool use, and the flows the agent follows during a live demo
• Work on our browser-use agent. River demos real products by controlling a browser live while it talks, and you'll teach it to navigate new products and complex UIs
• Build the enrichment pipeline that tells the agent who it's talking to before the call starts
• Partner with design partners on custom solutions, then generalize the wins back into the product
• Ship UI where it's needed (Next.js, React), watch real calls, and iterate fast