Founding Engineer

Join a small, early-stage team building an advertising technology platform. As Founding Engineer, you will own and develop the production recommendation system, with impact across data, machine learning, and real-time ad delivery.

• Design and ship a low-latency ad ranking system that selects campaigns and creative for each opportunity while balancing advertiser performance and user experience.

• Build data pipelines and feature infrastructure for ongoing model training across signals such as clicks, installs, and conversions.

• Model user behavior and context using engagement history, conversational data, and signals such as geography, device, and session activity.

• Develop efficient ad-serving infrastructure designed for sub-second latency and cost-conscious operation.

• Build generative agents that create playable and video ad variants, and feed their performance back into the recommendation system.

On-site in San Francisco, California, United States, five days per week.

• Typically 0 to 3 years of experience, with demonstrated ability to own substantial engineering work.

• Experience shipping an ML or AI system to production, ideally owning the full path from data pipelines and model training through serving.

• Strong backend, data infrastructure, and production serving skills, including experience with systems operating at significant scale.

• Ability to reason from first principles and work across infrastructure, classical machine learning, and AI agents.

• Experience with recommendation systems, ranking, advertising technology, or consumer products is useful; gaming interest and experience with playable ads are also valued.

• PyTorch experience and an active GitHub profile or shipped side projects demonstrating technical work are welcome.

• Must be a U.S. citizen or permanent resident and able to work on-site in San Francisco five days per week.

Base salary is $200,000 to $250,000 annually, plus equity. Visa sponsorship is not available.