Senior Machine Learning Engineer - Economy ML

Roblox•San Mateo, CA

5d•$260,300 - $312,970•Onsite

About The Position

The Economy ML team builds machine learning systems for Roblox’s virtual economy, including intelligent pricing, personalized storefronts, dynamic layout optimization, and avatar content understanding. The Senior Machine Learning Engineer will build models that power ranking, personalization, pricing, and optimization across Marketplace, Developer Monetization, and Payments. This work shapes how users discover virtual items, how creators earn, and how the platform grows sustainably. The role involves designing modern retrieval, ranking, and generative recommendation models, and making them efficient to train and serve at scale. The engineer will own end-to-end ML solutions, from exploring data and features through modeling, evaluation, and production deployment. They will develop pricing and revenue optimization models and policies while balancing ecosystem health, payer experience, and creator success; design experiments tied to engagement, bookings, and creator earnings; monitor production models; and collaborate across product and technical teams. The role also contributes to the team’s technical direction and includes mentoring other engineers.

Requirements

At least 3 years of industry experience building recommendation, search, or ranking systems for a high-scale product.
Hands-on expertise in modern recommender architectures, such as sequence models of user behavior, multi-task ranking, and large sparse embeddings.
Experience making recommender models efficient to train and serve, including comfort with multi-GPU training and tradeoffs between model quality, latency, and cost.
Ability to take ML problems from messy data and product ambiguity through modeling, evaluation, and stable production deployment.
Strong coding skills in Python and PyTorch.
Ability to reason about how model choices affect user, creator, and business metrics such as LTV, engagement, conversion, and creator earnings.
Comfort designing experiments, diagnosing metric movements, and iterating with statistical rigor and ecosystem guardrails.
Ability to work closely with engineers, product managers, data scientists, and designers and drive alignment across stakeholders.
Long-term perspective on the Roblox economy and ability to balance quick wins with foundational investments.

Nice To Haves

Experience with pricing or content understanding.
Experience applying LLM or multimodal techniques to recommendation.

Responsibilities

Design and iterate on retrieval, ranking, and generative recommendation models to personalize item and widget recommendations across Marketplace and other shopping experiences.
Make models efficient to train and serve at scale, considering compute, latency, and cost budgets and partnering with ML infrastructure engineers on distributed training and production serving.
Design and ship end-to-end ML solutions across Economy surfaces, owning 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 A/B tests and multi-cell experiments, tying work to metrics such as engagement, bookings, and creator earnings.
Monitor production models for data and prediction quality, identify drift and regressions, and help define on-call practices for ML services.
Partner with Product, Backend, Data Science, Design, and Marketplace and Economy teams to define roadmaps, requirements, and success metrics for ML-driven features.
Help shape the team’s modeling roadmap, experimentation strategy, and approaches to long-term reward optimization across the economy.
Mentor engineers through design reviews, code reviews, and hands-on guidance.