Recommendation Systems are a key growth lever at Roblox, driving retention, engagement, and monetization for hundreds of millions of users. This role offers the unique opportunity to redefine how users search and discover everything from the most interesting immersive experiences and digital avatars in our Marketplace to personalized advertising. You will solve a diverse range of high-scale ranking, retrieval, and personalization problems across our platform. We combine cutting-edge research —including deep learning, generative AI, and reinforcement learning techniques— with large-scale engineering to bridge experimentation and production; you'll design algorithms that operate at massive scale and shape the next generation of recommender systems for user-generated content. Teams Hiring for This Role Discovery: powers major search and recommendation surfaces—drives user engagement by redesigning core surfaces and search/homepage ranking Economy: builds the ML backbone for marketplace, monetization, and commerce (including fraud, pricing, and bundling) Ads & Brands: focuses on ranking, retrieval, and marketplace/auction theory to optimize sponsored content delivery. Safety, Critical Harms: focuses on proactively identifying and mitigating extremely high-risk, sensitive content and behaviors using investigative multi-step reasoning, behavior analysis, and knowledge graphs for risk forecasting.