Principal Machine Learning Engineer (AI)

TL;DR

Principal Machine Learning Engineer (AI): Architecting and building an industry-leading alternate account detection system to prevent recidivism at a massive scale with an accent on Graph Neural Networks (GNNs) and adversarial detection. Focus on mapping relationships across billions of entities, optimizing for low-latency detection, and developing robust defenses against sophisticated bad actors.

Location: Hybrid in San Mateo, CA (Onsite Tue-Thu). Must have US work authorization; H-1B sponsorship may not be available at this time.

Company

Roblox is a global platform empowering millions of users to create, explore, and share immersive 3D experiences.

What you will do

• Lead the technical vision for the alternate account detection platform, transitioning from reactive measures to proactive, near real-time prevention.
• Architect high-scale ML systems using Graph Neural Networks (GNNs) and advanced clustering to map relationships across billions of entities.
• Solve complex ground truth and training data challenges specifically for adversarial use cases.
• Build and optimize for low latency to ensure detection occurs within minutes of a bad actor's attempt to rejoin the platform.
• Develop innovative adversarial approaches to stay ahead of evolving identity-masking techniques.
• Mentor and up-level a pod of high-performing ML and software engineers to foster technical excellence.

Requirements

• 10+ years of industry experience in Applied ML with a significant focus on anti-abuse, fraud, integrity, or identity.
• MS or PhD degree in Computer Science, Machine Learning, or a related field.
• Deep expertise in Large-scale GNNs (e.g., GraphSAGE, PGB) and unsupervised/semi-supervised clustering at a scale of billions of nodes.
• Proven track record of leading complex technical projects from conception to production-level deployment.
• Experience with high-throughput systems and deploying ML models in low-latency environments.
• Must be based in or able to work from the San Mateo, CA office (Hybrid).

Culture & Benefits

• Hybrid work arrangement: onsite Tuesday, Wednesday, and Thursday, with optional presence on Monday and Friday.
• Competitive compensation package including base salary and equity.
• Comprehensive benefits as part of a full-time employment contract.
• Opportunity to solve unique technical challenges at a massive scale for a billion-user vision.