Senior Machine Learning Engineer, Behavioral Detection

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.

As a Senior Machine Learning Engineer on the Engine Security Behavioral Detection team, you will focus on building scalable ML systems to detect malicious behavior, automated play, and exploits using real-time or offline analysis to ensure platform safety and integrity. You will be at the forefront of protecting the Roblox community, developing sophisticated models that distinguish between legitimate player interactions and adversarial activities in a massive, dynamic 3D ecosystem. You will own the lifecycle of detection models, from identifying emerging threat patterns to deploying high-throughput inference services. Your work will bridge the gap between complex behavioral analysis and system-wide mitigation, ensuring that Roblox remains a safe and fair environment for millions of creators and players globally.

You Will:

• Design and implement end-to-end ML pipelines for anomaly detection and behavior analysis.
• Develop and deploy models that can identify complex, adversarial bot patterns and game exploits.
• Work on real-time or offline inference systems that can mitigate malicious activity without disrupting user experience.
• Collaborate with security teams, data scientists, and backend engineers to harden the platform against evolving threats.

You Have:

• PhD or Master’s in Computer Science, Data Science, or related field.
• 4+ years of experience in ML engineering, specifically in behavior modeling, anomaly detection, or fraud detection.
• Proficiency with time-series analysis, neural networks, or large-scale classification systems.
• Experience training and deploying models on high-throughput, low-latency production systems.
• Proficiency in Python (PyTorch/TensorFlow) and familiarity with big data processing frameworks (e.g., Spark, Flink, or similar).
• Strong problem-solving skills and a passion for platform integrity and security.

Job Expectations:

• Deliver high-impact ML solutions that directly improve platform security and trust.
• Take ownership of model monitoring and retuning strategies to counter adaptive adversary tactics.
• Provide technical guidance on best practices for feature engineering in adversarial domains.
• Maintain operational excellence, ensuring reliability and scalability of detection services.

For roles that are based at our headquarters in San Mateo, CA: The starting base pay for this position is as shown below. The actual base pay is dependent upon a variety of job-related factors such as professional background, training, work experience, location, business needs and market demand. Therefore, in some circumstances, the actual salary could fall outside of this expected range. This pay range is subject to change and may be modified in the future. All full-time employees are also eligible for equity compensation and for benefits as described on this page.

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

Roblox provides equal employment opportunities to all employees and applicants for employment and prohibits discrimination and harassment of any type without regard to race, color, religion, age, sex, national origin, disability status, genetics, protected veteran status, sexual orientation, gender identity or expression, or any other characteristic protected by federal, state or local laws. Roblox also provides reasonable accommodations to candidates with qualifying disabilities or religious beliefs during the recruiting process.

For US based roles only, please note the Company may not be able to employ candidates for this role who have United States work authorization related to certain U.S. visa categories, or support future H-1B sponsorship at this time.