Senior Machine Learning Engineer - Economy ML

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 Economy ML team is building the machine learning backbone for Roblox’s virtual economy—from intelligent pricing and personalized storefronts to dynamic layout optimization and avatar content understanding. We partner closely with Marketplace, Payments, and Developer Monetization to deliver ML systems that drive long‑term value across engagement, retention, and creator earnings. As a Senior Machine Learning Engineer on the team, you will build models that power ranking, personalization, pricing, and optimization across Roblox’s economic surfaces, including Marketplace, Developer Monetization, and Payments. Your work will directly shape how users discover virtual items, how creators earn, and how the platform grows sustainably. You Will: • Design and iterate on modern retrieval, ranking, and generative recommendation models (e.g., transformer-based sequential models over user behavior) that personalize item and widget recommendations across the Marketplace and other shopping experiences. • Make these models efficient to train and serve at scale: choose architectures and modeling approaches with compute, latency, and cost budgets in mind, and partner with ML infrastructure engineers on distributed training and production serving. • Work backwards from ambiguous product problems and opportunities to design and ship end‑to‑end ML solutions across Economy surfaces, owning the full lifecycle: data and feature exploration, modeling, evaluation, and production deployment on Roblox’s ML platform. • Develop models and policies that optimize pricing, conversion, and revenue while balancing ecosystem health, payer experience, and creator success. • Design and run robust experiments (A/B tests and multi‑cell experiments), tying your work to core metrics such as engagement, bookings, and creator earnings. • Keep models healthy in production: set up monitoring for data and prediction quality, catch drift and regressions early, and help define the team’s on-call practices for ML services. • Partner cross‑functionally with Product, Backend, Data Science, Design, and other Marketplace / Economy teams to define roadmaps, requirements, and success metrics for ML‑driven features. • Contribute to the technical direction of the Economy ML team: help shape our modeling roadmap, experimentation strategy, and approaches to long‑term reward optimization across the economy. • Mentor other engineers through design reviews, code reviews, and hands-on guidance, helping raise the technical bar of the broader Economy organization. You Have: • 3+ years of industry experience building recommendation, search, or ranking systems for a high-scale product. Experience with pricing or content understanding is a plus. • Deep, hands-on expertise in modern recommender architectures (e.g., sequence models of user behavior, multi-task ranking, large sparse embeddings) and in making them efficient to train and serve: comfortable with multi-GPU training and with the tradeoffs between model quality, latency, and cost. Experience applying LLM or multimodal techniques to recommendation is a plus. • Fluent in the ML lifecycle: Comfortable taking a problem from messy data and product ambiguity through modeling, evaluation, and stable production deployment, with strong coding skills in Python and PyTorch. • You think in terms of impact on users, creators, and the business, and you can reason clearly about how model choices affect metrics like LTV, engagement, conversion, and creator earnings. • You are comfortable designing experiments, diagnosing metric movements, and iterating quickly while maintaining statistical rigor and healthy guardrails for the ecosystem. • You enjoy working closely with engineers, product managers, data scientists, and designers across Marketplace, Payments, and Developer Monetization, and you can drive alignment in complex, multi‑stakeholder environments. • You take a long‑term view of the Roblox economy, are comfortable challenging assumptions, and can balance quick wins with foundational investments in data, infrastructure, and modeling quality. 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 $260,300—$312,970 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 an