Founding Product Engineer

From the original posting

San Francisco ABOUT THE ROLE Join an early-stage consumer AI startup as its founding product engineer, with ownership of the AI agent and the user experience from end to end. You will work across product engineering, agent behavior, and evaluation, helping shape a personal assistant that can take useful actions while earning user trust. WHAT YOU'LL DO - Build the agent's decision-making system, including tool-calling loops, memory, context assembly, prompt design, and model routing. - Create evaluation tools such as turn-level judges, conversation replay, and regression suites to assess…