[2026] Senior Machine Learning Engineer, Recommendation Systems - PhD Early Career

About the role

This role offers the unique opportunity to redefine how users search and discover everything from the most interesting immersive experiences and digital avatars in our Marketplace to personalized advertising. You will solve a diverse range of high-scale ranking, retrieval, and personalization problems across our platform.

Responsibilities

• Design and implement large-scale recommendation systems that power discovery across Roblox’s surfaces — experiences, avatars, and creator content.
• Develop deep learning models for ranking, retrieval, and personalization using approaches in multimodal models, LLMs, and generative AI.
• Collaborate with applied researchers, engineers, and product teams to advance experimentation and accelerate innovation.
• Translate research into production systems that impact hundreds of millions of daily active users.
• Work backward from user and product needs to deliver ML solutions that drive engagement, retention, and ecosystem growth.

Requirements

Possessing or pursuing a PhD in computer science, engineering, or a related field, with a thesis aligned to Roblox’s research areas.

Expertise in one or more areas: recommender systems, search systems, information retrieval, or generative models (e.g., LLMs, VLMs, VLAs).

A strong research track record, evidenced by multiple publications and presentations in top-tier, peer-reviewed venues (e.g., SIGIR, KDD, RecSys, ICLR, ICML, NeurIPS).

Proficiency in one or more programming languages (e.g., Python, C++, Go, Java) and experience building and optimizing large-scale systems.

Qualifications

Experience with large-scale recommendation systems and understanding of user behavior and preferences.

Knowledge of machine learning algorithms and techniques, including deep learning, generative AI, and reinforcement learning.

Experience with data processing and analysis, including handling large datasets and implementing scalable solutions.

Skills

Strong problem-solving skills and ability to work independently and collaboratively.

Excellent communication and collaboration skills, both written and verbal.

Benefits

Roblox provides a competitive benefits package, including health insurance, retirement plans, and paid time off.

Pay

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.

Annual Salary Range $195,780—$242,100 USD

Schedule

Roles that are based in an office are onsite Tuesday, Wednesday, and Thursday, with optional presence on Monday and Friday (unless otherwise noted).