[2026] Senior Machine Learning Engineer, Account Identity - PhD Early Career

Every day, tens of millions of people come to Roblox to explore, create, play, learn, and connect with friends in 3D immersive digital experiences– all created by our global community of developers and creators. At Roblox, we’re building the tools and platform that empower our community to bring any experience that they can imagine to life. Our vision is to reimagine the way people come together, from anywhere in the world, and on any device. We’re on a mission to connect a billion people with optimism and civility, and looking for amazing talent to help us get there. A career at Roblox means you’ll be working to shape the future of human interaction, solving unique technical challenges at scale, and helping to create safer, more civil shared experiences for everyone. WHY SAFETY? At Roblox, we strive to connect a billion people with optimism and civility, and the Safety organization’s mission is to become the leader in civil immersive online communities. We systematically detect, remove, and prevent problematic accounts, content and behavior, and we make Roblox accounts secure and free from compromise. We cover a broad area of the tech spectrum, including machine learning, classifiers for 3D models, experimentation, automation, detection workflows, and AI-powered text filters. Aligned and partnering with product teams, we use this toolbelt to discover new opportunities, influence and shape the product roadmap and prioritization, build safety products, and measure the impact on our community of users and developers. In doing so, we keep Roblox safe, civil, and inclusive, and we foster positive relationships between people around the world. WHY ACCOUNT IDENTITY? Safety and Civility is Roblox's #1 priority. Our mission is to keep the platform secure by establishing a deep understanding of our users. As a Senior Machine Learning Engineer within the Account Identity team, you will be instrumental in developing our in-house Facial Age Estimation product and centralizing age assurance controls. If you are passionate about solving complex, high-impact problems in an adversarial landscape, this is the team for you. You Will: Develop cutting-edge defenses against complex fraud and identity spoofing, such as deepfake detection and facial representation systems, utilizing modern architectures like Vision-Language Models (VLMs) and multimodal learning. Build high-precision facial age estimation and real-time liveness checks that form the critical foundation of a safe, trusted platform for users. You Have: Possessing or pursuing a PhD in computer science, engineering, or a related field, with a thesis aligned to Roblox’s research areas. Expertise in one or more areas: computer vision, multimodal learning, deepfake detection, facial representation, adversarial machine learning, or VLM/LLM. Strong coding skills with proficiency in one or more programming languages and experience with building large-scale systems Experience working with large-scale data logs and tools like Spark and SQL to extract meaningful behavioral features. The ability to build and productionize end-to-end ML development life cycles, including data engineering and scoring algorithms. You Are: Resourceful: You're adaptable in any situation and can always find a path forward in the face of evolving threats. Analytical: Excited to investigate large, ambiguous datasets to find the "signal in the noise" of billions of accounts. User Oriented: You understand that safety measures must be balanced with a seamless experience for our legitimate community members. Team Oriented: You are a sought-after mentor who lifts up your peers and builds a collaborative, high-performance environment. Mission Oriented: You are laser-focused on keeping Roblox safe and are willing to take bold, strategic risks to achieve a billion-user scale safely. You may redact age, date of birth, and dates of attendance/graduation from your resume if you prefer. As you apply, you can find more information abou