Principal Machine Learning Engineer, Riot Games
League of Legends
$229.2-319.5k
+ Equity
Player-focused game development platform
Be an early applicant
Player-focused game development platform
1001+ employees
Be an early applicant
$229.2-319.5k
+ Equity
1001+ employees
Company mission
To be the most player-focused game company in the world.
Role
Who you are
- Extensive experience (8+ years) delivering ML systems in production, including reinforcement learning, imitation learning, or simulation-based training in rich, interactive environments such as game worlds or multi-agent simulations
- Proven ability to design modeling strategies and architectures adopted across multiple games or interactive products
- Expertise working with gameplay telemetry, simulation data, or other complex interactive environments for feature engineering and training
- Game engineering/C++ experience to write telemetry hooks is a plus
- Strong track record building and optimizing agent-based systems or world models for dynamic, player-facing environments
- Hands-on experience with relevant ML methods including reinforcement learning and imitation learning (such as behavior cloning and inverse reinforcement learning), on-/off-policy algorithms, policy gradient methods, behavior shaping, and hybrid systems that combine learned policies with rule-based or scripted components
- Mastery of experiment design, model evaluation, and optimization for autonomous agents
- Track record of incorporating human considerations into AI applications, such as responsible AI safety and UX best practices
- League of Legends game context and/or demonstrated ability to learn competitive game systems at a rapid rate.
- Familiarity with integrating ML-driven agents into live game environments with game and platform engineers
What the job involves
- As a Principal Machine Learning Engineer, you will unlock better Bots for League of Legends at a pivotal time in the game’s history
- You will be forming and testing various ML and AI approaches to training bots that can play with and against human players of varying skill and experience levels
- This is a key area of our product strategy and you will be at the forefront of us improving the player experience for millions of players across the globe
- Reporting directly into the game team, you will collaborate with game engineers, UX designers, and Insights analysts to test, optimize, and deploy your bot approaches utilizing live data and experimentation
- You could also be involved in building a variety of ML applications for League including but not limited to content generation, artist tools, and design tools
- Lead the modeling strategy for AI Bots on League of Legends, focusing on training agents that can understand game state, make decisions, and create compelling player experiences across a variety of game modes and skill levels
- Develop predictive features and signals from gameplay telemetry, unstructured game data, and simulation outputs, ensuring quality, interpretability, and reliability
- Design and implement ML systems using methods including reinforcement learning and imitation learning, on-/off-policy algorithms, policy gradient methods, behavior shaping, and hybrid systems that combine learned policies with rule-based or scripted components
- Define evaluation frameworks for game AI that balance generalizable approaches with genre-specific metrics, adapting methods for the needs of each game mode
- Ensure the safety, fairness, and trustworthiness of autonomous agents operating in live player environments
- Collaborate with game and platform engineers, along with UX teams, to integrate models into production in ways that enhance player experience and maintain operational reliability
- Contribute to the AI community at Riot, sharing methods and learnings with other MLEs across the company
Our take
Riot Games has grown into one of the world’s most prominent online and mobile game developers, due in large part to the success of its 2009 flagship title League of Legends which hosts over 120M users every month.
Riot is riding the wave of online gaming growth, having made a well timed switch from PC-only into mobile-based gaming, as capitalizing on the rising popularity of esports, with the League of Legends World Championships one of the most watched events in the space.
While expanding its portfolio with new titles has played a role in Riot's evolution, the company's continued success is more firmly rooted in the enduring strength of League of Legends itself. Riot has built a vast ecosystem around the game, from its global eSports tournaments tand regional leagues to its numerous brand partnerships and sponsorships. The League of Legends World Championship in particular remains a cultural and commercial powerhouse, drawing massive viewership and sustaining global engagement. And since its acquisition by Tencent in 2011, Riot has also expanded its presence in Asia, opening new studios in Shanghai and beyond, to further strengthen its site to markets where competitive gaming and eSports are deeply embedded.
Freddie
Company Specialist at Welcome to the Jungle
Insights
24% employee growth in 12 months
Company
Funding (2 rounds)
Sep 2009
$8m
SERIES C
Jul 2008
$7m
EARLY VC
Total funding: $15m
Company benefits
- Healthcare: Medical, dental, and vision plans that cover you as well as your spouse/domestic partner and children.
- Family Care: Life insurance, parental leave, plus short and long-term disability.
- Open Paid Time Off: In addition to holidays, a 2-week end of year break, and a 1-week mid-year break, Rioters are trusted to take the time they need throughout the year.
- Retirement: Riot matches retirement contributions so you can continue to play games long after you retire.
- Play Fund: Riot’s annual play fund allows Rioters to broaden their knowledge of the games that matter to players and the community.
- Donation Matching: Riot matches donations of time and money to nonprofits to double down on support.
Company HQ
Sawtelle, Los Angeles, CA
Leadership
Brandon Beck
(Co-Founder & Co-Chairman)Prior to co-founding Riot Games in 2006, Brandon was a Management Consultant at Bain & Company.
Marc Merrill
(Co-Founder, CPO & Co-Chairman)After a degree at the University of Southern California, they worked as a U.S. Bank Analyst and a Manager of Advanstar Communications. They co-founded Riot Games with Brandon in September 2006, alongside being a Principal of NaHCo3 since 2016.
A. Dylan Jadeja
(CEO)Dylan joined the Riot team in 2011 as CFO and COO, becoming CEO in 2023. Prior to this, he spent 7 years at Goldman Sachs as a VP and nearly 4 years at A.T. Kearney as a Senior Associate.
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