Founding Product Engineer

ABOUT THE ROLE Join an early-stage consumer AI company as its founding product engineer, owning the agent and the end-to-end user experience. You will shape how the assistant makes decisions, communicates, and takes action, while working hands-on across product engineering, prompts, and evaluation systems. WHAT YOU'LL DO - Build the agent decision-making layer, including tool-calling loops, memory, context assembly, prompt engineering, and model routing. - Create evaluation infrastructure with conversation replay, turn-level judging, and regression suites to guide release decisions. - Own mobile and web product experiences, from onboarding and first interactions through ongoing use, group conversations, approvals, and trusted connections. - Ship features end to end, using experimentation and feature flags to measure their impact. - Develop integrations with email, calendars, bookings, payments, and browser automation, including OAuth and spending approval flows. - Review conversations and speak with users regularly to inform product decisions. - Establish engineering standards and help grow the team.

WHAT WE'RE LOOKING FOR - At least 4 years of software engineering experience, including work at an AI product company, AI lab, or consumer product company. - Production experience building agents with tool use, long-running conversations, and memory, along with evaluation systems used to inform shipping decisions. - Full-stack experience with TypeScript, React, Next.js, and PostgreSQL. - Experience with third-party APIs, OAuth, payments, or LLM agent tooling such as function calling, MCP servers, or browser automation. - A record of owning features end to end and delivering measurable product impact, with strong product and design judgment. - Comfort using AI-assisted development workflows while verifying and taking ownership of shipped code.

Post-training or fine-tuning experience is a plus. COMPENSATION & BENEFITS Salary range: $200,000 to $300,000 USD annually. Visa sponsorship is not available. LOCATION On-site in San Francisco, California, United States.