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

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.

Recommendation Systems are a key growth lever at Roblox, driving retention,

engagement, and monetization for hundreds of millions of users. 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.

We combine cutting-edge research —including deep learning, generative AI, and

reinforcement learning techniques— with large-scale engineering to bridge

experimentation and production; you'll design algorithms that operate at massive

scale and shape the next generation of recommender systems for user-generated

content.

TEAMS HIRING FOR THIS ROLE

* Search and Discovery: powers major recommendation surfaces—conducting

cutting-edge research in generative modeling, multimodal and MLLM

technologies, designing advanced agentic AI algorithms to solve business

requirements while achieving technical breakthroughs.

* Safety, Alt Defense: architects a massive-scale detection engine that

identifies recidivist bad actors across billions of accounts to ensure the

long-term integrity of the Roblox community.

You Will

* 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.

You Have

* 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)

* Ability to design and architect systems for efficient personalization and

user interest modeling using advanced attention mechanisms (e.g.,

sparse/linear attention).

* 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.

Apply now to be considered for anticipated positions.

You may redact age, date of birth, and dates of attendance/graduation from your

resume if you prefer.

As you apply, you can find more information about our process by signing up for

Speak_. You'll gain access to our practice assessment, comprehensive guides,

FAQs, and modules designed to help you ace the hiring process.

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 [https://careers.roblox.com/total-rewards].

Annual Salary Range

$195,780—$242,100 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.