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. 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 . Annual Salary Range $196,750 — $243,290 USD 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.