Principal Machine Learning Engineer, Content Safety

About the Role

As a Principal Machine Learning Engineer for Content Safety, you will define the future of proactive moderation, driving immense social impact through cutting-edge, innovative ML solutions, focused on critical and ambiguous safety challenges. You will set the 3-5 year technical strategy and architectural blueprint for how Roblox uses machine learning for content moderation. You will own the architectural and execution roadmap of massive-scale ML systems that mitigate violative UGC content before it impacts our community. You will feel a deep sense of responsibility in proactively protecting our community thoughtfully and fairly, while balancing user freedom with platform civility. Your efforts will ensure Roblox remains one of the safest places on the internet for our broad community of over 100 million daily active users.

Responsibilities

• Define and lead the multi-year technical vision, architectural strategy, and execution for machine learning solutions in Content Safety, ensuring these systems proactively and effectively detect and mitigate violative content at massive scale.
• Collaborate with executive-level Product, Data Science, Policy, and Operations leaders to define and prioritize the strategic machine learning roadmap, influencing product strategy and demonstrating the impact of ML on user trust and safety outcomes.
• Oversee the adoption and safe deployment of innovative machine learning techniques (e.g., transfer-learning, self-supervised learning, quantization, LoRA, distillation).
• Drive end-to-end product development: construct datasets from scratch where none exist, build auto-labeling pipelines, and ship solutions to solve novel technical problems.
• Integrate your work into the production stack, spending roughly 30-40% of your time on backend and integration work, leveraging modern AI coding tools (e.g., Cursor) to accelerate velocity and handle infrastructure complexity.

Qualifications

• 8+ years of experience designing, developing, and operating large-scale, high-impact machine learning systems in a production environment.
• Proven track record of successfully setting the long-term technical direction for an entire ML domain, demonstrating the ability to take ambiguous problems from concept to scaled production impact.
• Deep expertise in advanced ML architectures and techniques, including Computer Vision (CV) and/or Vision-Language Models (VLMs).
• Expertise in architecting scalable, real-time ML inference services and robust data pipelines.
• Demonstrated success in leading and resolving high-stakes, cross-functional conflicts and technical disagreements, with an ability to build consensus among diverse stakeholders.
• Exceptional product sense and strategic planning ability: able to translate platform safety requirements into an achievable, iterative technical roadmap.

You Are

• A visionary architect capable of synthesizing complex business and safety goals into a clear, compelling, and actionable technical strategy.
• A pragmatic builder: scrappy and impact-oriented, viewing undefined data and messy systems as opportunities to build structure rather than blockers to progress.
• Comfortable with ambiguity: you thrive in undefined or open-ended problem spaces, providing structure, clarity, and decisive direction to your teams.
• An inspiring leader passionate about developing the next generation of technical leaders, managers, and engineers.
• An executive communicator highly effective at communicating complex technical concepts to both engineering teams and non-technical executive leadership.
• Committed to Ethical AI: dedicated to building ML systems that are fair, transparent, and operate with the utmost responsibility toward user safety and platform civility.

Pay

• Annual salary range: $295,250—$345,040 USD
• All full-time employees are also eligible for equity compensation

Schedule

Roles that are based in an office are onsite Tuesday, Wednesday, and Thursday, with optional presence on Monday and Friday.