Principal Machine Learning Engineer, Content & Communication Safety

Why Safety

At Roblox we strive to connect a billion people with optimism and civility and the Safety organizations mission is to become the leader in civil immersive online communities. We systematically and proactively detect remove and prevent problematic content and doing so we keep Roblox safe civil and inclusive fostering positive relationships between people around the world.

Why Safety AI Systems

As a Senior/Principal Machine Learning Engineer for Safety AI Systems you will define the future of proactive moderation driving immense social impact through cutting-edge innovative ML solutions. This role is a fusion of a Principal Engineers technical authority and an Engineering Managers leadership focused on the most critical and ambiguous safety challenges.

You will set the 3-5 year technical strategy and architectural blueprint for how Roblox uses machine learningfrom high-velocity text filtering to leveraging multimodal Generative AIto combat the most complex critical harms on the platform. You will own the execution roadmap and technical planning directly guiding the launch of high-priority new ML projects. You will be responsible for defining the standards of innovation in data quality model robustness and ethical deployment across the entire Content & Communication Safety ML pillar.

You will lead and scale a high-performing group of individual contributors providing both strategic oversight and hands-on guidance to the teams responsible for the architectural development of massive-scale systems that mitigate abuse and harassment before it impacts our community.

You will feel a deep sense of responsibility in proactively protecting our communitythoughtfully and fairlywhile balancing user freedom with platform civility. Your efforts will ensure Roblox remains one of the safest places on the internet for users.

You will:

• Define and Own the Technical Vision: Define and lead the multi-year technical vision architectural strategy and execution for machine learning solutions across Content and Communication Safety ensuring these systems proactively and effectively detect and prevent high-severity critical harms at massive scale.
• Provide Senior/Principal-Level Architecture: Act as the highest technical authority for the Content Safety ML domain guiding the architecture and long-term maintainability of foundational models data pipelines and real-time inference services.
• Drive Cross-Org Alignment: Identify and champion the most ambiguous high-leverage technical problems driving alignment and securing investment for organization-wide ML infrastructure and platform development initiatives that benefit all of Trust & Safety.
• Lead Innovation in Safety: Oversee the adoption and safe deployment of innovative technologies (e.g. advanced NLP self-supervised learning multimodal LLMs) to anticipate and mitigate novel abuse vectors moving beyond reactive detection to proactive intervention.
• Strategic Stakeholder Partnership: 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.

You have:

• 8 years of experience designing developing and operating large-scale high-impact machine learning systems in a production environment.
• 5 years of experience in technical leadership management or mentorship roles ideally having managed Engineering Managers or Senior/Principal-level individual contributors.
• A proven track record of successfully setting the long-term technical direction for an entire ML domain or pillar demonstrating the ability to take ambiguous problems from concept to scaled production impact.
• Deep expertise in advanced ML architectures including Large Language Models (LLMs) transfer learning or other foundation model technologies especially applied to text or multimodal data.
• Expertise in architecting scalable real-time ML inference services and robust data pipelines operating at millions of requests per second.
• 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.
• An Inspiring Leader: Passionate about developing the next generation of technical leaders managers and engineers.
• Comfortable with Ambiguity: You thrive in undefined or open-ended problem spaces providing structure clarity and decisive direction to your teams.
• 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.

Required Experience:

Staff IC