ML engineers at Riot own the full lifecycle of machine learning in production - from problem framing through model design, deployment, and operation - building systems that serve players at global scale. They work across disciplines with engineers, data scientists, designers, and product teams to turn ML capabilities into player-facing experiences and tools for making great games.

As a Staff Applied Modeling Engineer on an unpublished R&D product, you will lead the modeling strategy for the team - establishing architecture patterns, setting standards, and continuing to design solutions for the highest-complexity problems directly. Your work will span multi-month efforts and across multiple disciplines, shaping how the team (and Riot) approach applied ML. You will report to the Senior Engineering Manager of the Tech Foundations team within an R&D game project.

Responsibilities:

Work closely with designers, artists, and other engineers to discover and conceptualize opportunities for AI-powered workflow enhancements
Establish AI/ML architecture patterns within the project and design solutions for high-complexity problems; guide solution design considering integration and operational constraints
Refine modeling and feature invention strategy for the project; improve architecture trade-offs, signal extraction techniques, and quality standards for complex data sources
Refine multi-model system design and model optimization; improve interaction analysis, dependency management, and performance evaluation techniques
Establish pipeline architecture patterns within the project, aligning with Riot’s shared tech ecosystem; guide workflow design and deployment automation; set reliability standards
Establish research-to-production practices in partnership with research scientists; balance cutting-edge techniques with production reliability
Elevate the team’s expertise in advanced AI/ML methods for game development through mentorship and documentation, and contribute to team health through cross-disciplinary collaboration; level up developers across discipline

Required Qualifications:

Bachelor’s degree or higher in Computer Science, Machine Learning, Statistics, or a related quantitative field, or equivalent practical experience
6+ years of experience delivering ML systems in production, including 3+ years in applied modeling or ML research roles
Evidence that your modeling choices have been adopted beyond your immediate team - whether through reusable patterns, shared architectures, or influence on how others approach problems
History of working with complex or unconventional data sources where off-the-shelf feature engineering doesn’t apply
Experience in production environments with interacting models, feedback loops, or systems where model behavior has downstream consequences beyond a single prediction
Comfort with ambiguity - you’ve shipped in situations where the success metric, the right approach, or both were unclear at the start.
Track record mentoring engineers across roles and levels; evidence of raising the bar for people around you.
Strong written and verbal communication skills across technical and non-technical audiences
Passion for player experience, games, or creative technology
Proficiency in C++

Desired Qualifications:

Background in reinforcement learning, imitation learning, generative models, or simulation-based training in interactive environments
Familiarity with ML platform components (model serving, feature stores, ML observability)
Experience working in a AAA game engine (i.e. Unreal)
Experience building multiplayer games
Experience implementing tools for game designers and/or artists
Experience mentoring technical ICs and contributing to engineering culture

For this role, you'll find success through craft expertise, a collaborative spirit, and decision-making that prioritizes the delight of players. We will be looking at your past studies, experience, and your personal relationship with games. If you embody player empathy and care about players' experiences, this could be your role!

Our Perks:

Riot focuses on work/life balance, shown by our open paid time off policy and other perks such as flexible work schedules. We offer medical, dental, and life insurance, parental leave for you, your spouse/domestic partner, and children, and a 401k with company match. Check out our benefits pages for more information.

At Riot Games, we put players first. That mission drives every decision in our quest to create games and experiences that make it better to be a player. Whether you’re working directly on a new player-facing experience or you’re supporting the company as a whole, everyone at Riot is part of our mission. And just like in our games, we’re better when we work together. Our goal is to create collaborative teams where you are empowered to bring your unique perspective everyday. If that sounds like the kind of place you want to work, we’re looking forward to your application.

It’s our policy to provide equal employment opportunity for all applicants and members of Riot Games, Inc. Riot Games makes reasonable accommodations for handicapped and disabled Rioters and does not unlawfully discriminate on the basis of race, color, religion, sex, sexual orientation, gender identity or expression, national origin, age, handicap, veteran status, marital status, criminal history, or any other category protected by applicable federal and state law. We consider for employment all qualified applicants, including those with criminal histories, in a manner consistent with applicable federal, state and local law, including the California Fair Chance Act, the City of Los Angeles Fair Chance Initiative for Hiring Ordinance, the Los Angeles County Fair Chance Ordinance for Employers, the San Francisco Fair Chance Ordinance, and the Washington Fair Chance Act.

Per the Los Angeles County Fair Chance Ordinance, the following core duties may create a basis for disqualifying candidates with relevant criminal histories:

Safeguarding confidential and sensitive Company data
Communication with others, including Rioters and third parties such as vendors, and/or players, including minors
Accessing Company assets, secure digital systems, and networks
Ensuring a safe interactive environment for players and other Rioters

These duties are directly related to essential operations, safety, trust, and compliance obligations within our organization. Please note that job duties may evolve based on business needs and additional responsibilities may be assigned as necessary to maintain operational efficiency and security.

Staff Applied Modeling Engineer - Unpublished R&D Product