Senior Machine Learning Infrastructure Engineer

Required

• 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 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.