Senior Machine Learning Engineer - Economy ML

Roblox; San Mateo (CA); On-site; USD 260,000 - 313,000; Full time

Job summary

Roblox Corporation is seeking a Senior Machine Learning Engineer for the Economy ML team. You will build models powering ranking, pricing, and optimization across Marketplace, Developer Monetization, and Payments, shaping how users discover items and how creators earn on Roblox’s platform.

The role emphasizes end-to-end ML solutions, production readiness in Python/PyTorch, and collaboration with cross-functional teams to drive business impact.

Qualifications

• 3+ years of industry experience building recommendation, search, or ranking systems for a high-scale product.
• Deep, hands-on expertise in modern recommender architectures and in making them efficient to train and serve.
• Fluent in the ML lifecycle: problem to production deployment with strong Python and PyTorch skills.
• Experience applying LLM or multimodal techniques to recommendation is a plus.

Responsibilities

• Design and iterate on retrieval, ranking, and generative recommendation models that personalize item recommendations across the Marketplace and shopping experiences.
• Make models efficient to train and serve at scale with attention to compute, latency, and cost budgets.
• Own end-to-end ML solutions across Economy surfaces from data exploration to production deployment on Roblox’s ML platform.
• Develop models and policies that optimize pricing, conversion, and revenue while balancing ecosystem health and creator success.
• Design and run robust experiments (A/B tests and multi-cell experiments) tied to metrics like engagement and creator earnings.
• Keep production models healthy through monitoring, drift detection, and on-call practices for ML services.

Skills

Recommendation systems

Python

PyTorch

Multi-GPU training

Experimentation

Tools

Python

PyTorch

Job description

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.

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 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.