Founding Product Engineer

ABOUT THE ROLE Join an early-stage personal AI assistant team as its founding product engineer. You will own the agent and user experience end to end, helping shape how the assistant makes decisions, communicates, and takes action. WHAT YOU'LL DO - Build the agent decision-making layer, including tool-calling loops, memory, context assembly, prompts, and model routing. - Create evaluation infrastructure with conversation replay, turn-level judges, and regression suites to guide release decisions. - Own product experiences across mobile and web, from onboarding and initial replies to follow-ups, group chats, approvals, and trusted-network features. - Ship features end to end, using experimentation and feature flags to measure outcomes. - Build integrations with email, calendar, booking, payment, and browser tools, including resilient workflows and user approval steps. - Review conversation transcripts, speak with users, and use feedback and product data to guide priorities. - Set engineering standards and help grow the team while staying hands-on. WHAT WE'RE LOOKING FOR - At least 4 years of software engineering experience at an AI product company, AI lab, or consumer product company. - Production experience building agents with tool use, memory, and long-running conversations, plus evaluation systems that support release decisions. - Full-stack skills with TypeScript, React, Next.js, and PostgreSQL. - Experience with third-party APIs, OAuth, or payments, and agent tooling such as function calling, MCP servers, or browser automation. - A record of owning features end to end and demonstrating measurable product impact. - Strong product judgment and experience shipping user-facing AI products, ideally for consumer audiences. - Comfort with AI-assisted development workflows and the fundamentals needed to verify and own shipped work. - Post-training or fine-tuning experience is a plus. COMPENSATION & BENEFITS Base salary: $200,000 to $300,000 annually. Visa sponsorship is not available. LOCATION On-site in San Francisco, California.