Senior Software Engineer - NPC Behavior

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.

The Creator Service NPC team is the heartbeat behind our worldwide gaming experiences. We aim to build the best NPC tools for creators. Our product covers play testing, in game NPC as well as digital players. We are using technologies from LLM, Imitation Learning, Reinforcement Learning, Behavior Trees, Statement Machines. As a Senior Software Engineer, you will design and build highly scalable systems to help creators to continuously deliver experiences that feel native and seamless. You will help us to build and maintain data pipelines, visualisation, feature transformation, annotation tools and work on inference set ups within and on top of our game engine.

Join us if you thrive on cross‑functional collaboration, care about building the smartest NPCs and digital players, and want to shape how millions of players experience our worlds, and everywhere in between.   

You Will:

• Tackle and solve challenging full-stack problems that touch the client, game engine, backend services and machine learning models.


• Own product areas and projects from technical design, execution, launch, and quick iteration based on feedback.


• Work closely with product, design, and partner teams to maintain high execution quality and pace.


• Proactively gather community feedback and respond swiftly to their needs, ensuring our products evolve to deliver exceptional value.

You Have:

• Experience: You have 5+ years of experience and you’ve designed and led implementation on highly scalable and reliable distributed backend systems. You have hands-on experience in microservices. You have hands-on experience with game engines.


• Knowledge: You are proficient in one or more programming languages (C#, Lua, C++, Go, Python or similar programming language). Deep understanding of C++ is a plus, familiarity with game engines is a plus, familiarity with machine learning is a plus.


• Curiosity: You are curious and passionate about industry trends and new technologies, you are able to apply them to practical problems innovatively. 


• Strong Teamwork: You are able to drive cross-functional projects and collaborate with teams to deliver the most curated technical solution.


• Long-term Mindset: You are willing to take the long-term to build the system, and your design choices and technical solutions are usually still optimal multiple years into the future.