Founding Engineer

About the Role Join an early-stage advertising technology team building an ad recommendation and serving platform for AI entertainment and mobile gaming. As a Founding Engineer, you will own systems that select and deliver relevant interactive ads in real time, working across data, machine learning, and production infrastructure. What You'll Do Design and ship low-latency retrieval, ranking, and reranking systems that select campaigns and creative while balancing advertiser performance with user experience. Build data pipelines and feature infrastructure for continuous model training across clicks, installs, and conversions. Develop user and context representations from conversational signals, engagement history, device, location, session, and interaction data. Build cost-efficient serving infrastructure that meets sub-second latency requirements. Create generative agents that produce playable and video ad variants, and feed performance signals back into recommendation systems. What We're Looking For Typically 0 to 3 years of experience, with hands-on experience shipping at least one machine learning or AI system to production. End-to-end experience building data architecture, feature pipelines, and serving infrastructure, in addition to developing models. Strong generalist engineering skills across backend systems, machine learning, and infrastructure, with experience using PyTorch. Experience with recommendation systems, ranking, or advertising technology is valuable. Active GitHub or side projects demonstrating work across backend, ML, and infrastructure. Interest in gaming, including experience with League of Legends or mobile games and rewarded ads. Consumer technology or advertising infrastructure experience is relevant. Compensation & Benefits Base salary: $200,000 to $250,000 annually. Visa sponsorship is not available. Location On-site in San Francisco, California, five days per week.