Principal Machine Learning Engineer (Content Safety)

TL;DR

Principal Machine Learning Engineer (Content Safety): Defining the 3-5 year technical strategy and architectural blueprint for ML-based content moderation with an accent on proactive detection of violative UGC at massive scale. Focus on building high-impact ML systems, implementing CV/VLM architectures, and integrating models into the production backend.

Location: Hybrid in San Mateo, CA (Onsite Tuesday, Wednesday, and Thursday)

Company

Roblox is a global platform that empowers its community to create and share immersive 3D experiences.

What you will do

• Define and lead the multi-year technical vision, architectural strategy, and execution for ML solutions in Content Safety.
• Collaborate with executive-level Product, Data Science, and Policy leaders to prioritize the strategic ML roadmap.
• Oversee the adoption and deployment of innovative techniques such as transfer-learning, self-supervised learning, and LoRA.
• Build end-to-end product solutions, including dataset construction and auto-labeling pipelines.
• Handle backend and integration work (approximately 30-40% of time) to ship solutions into the production stack.

Requirements

• 8+ years of experience designing and operating large-scale ML systems in production.
• Proven track record of setting long-term technical direction for an entire ML domain.
• Deep expertise in Computer Vision (CV) and/or Vision-Language Models (VLMs).
• Expertise in architecting scalable, real-time ML inference services and robust data pipelines.
• Must be based in San Mateo, CA, or able to work onsite Tue-Thu.
• Valid US work authorization is required.

Culture & Benefits

• Opportunity to shape the future of human interaction and digital safety for over 100 million daily users.
• Work environment that values ethical AI, fairness, and transparency.
• Competitive base pay and equity compensation for full-time employees.
• Flexible presence on Mondays and Fridays for office-based roles.