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Roku

Senior Machine Learning Engineer - Search

Hybrid

Cambridge, United kingdom

Senior

Full Time

08-10-2025

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Skills

Communication Teamwork Leadership Python Java Scala Big Data Problem-solving Presentation Skills Attention to detail Motivation Architecture Machine Learning Deep Learning Analytical Thinking Spark NLP

Job Specifications

Teamwork makes the stream work.Roku is changing how the world watches TV

Roku is the #1 TV streaming platform in the U.S., Canada, and Mexico, and we've set our sights on powering every television in the world. Roku pioneered streaming to the TV. Our mission is to be the TV streaming platform that connects the entire TV ecosystem. We connect consumers to the content they love, enable content publishers to build and monetize large audiences, and provide advertisers unique capabilities to engage consumers.

From your first day at Roku, you'll make a valuable - and valued - contribution. We're a fast-growing public company where no one is a bystander. We offer you the opportunity to delight millions of TV streamers around the world while gaining meaningful experience across a variety of disciplines.



About the team

Roku is the No. 1 TV streaming platform in the U.S., Canada, and Mexico with 70+ millions of active accounts. Roku pioneered streaming to the TV and continues to innovate and lead the industry. We believe Roku's continued success relies on its investment in our machine learning/ML recommendation engine. Roku enables our users to access millions of contents including movies, episodes, news, sports, music and channels from all around the world.



About the role

The depth of query, content and user understanding using ML is key to user happiness in their search journey. Solving this customer problem is why we're actively looking for a Senior Machine Learning Engineer, Search & Recommendations to drive further innovation in search and discovery. The person in this role will leverage their technical skills, business intuition, and analytical thinking to build best of class AI powered products. Hence, communication and presentation skills are important. The role requires both high technical acumen and problem-solving abilities, motivation, and exceptional attention to detail. Every day, you'll look at what exists and find ways to make it better.



What you'll be doing
Apply state of the art ML on search using techniques in deep learning, bandits, transformers, LLMs, causal inference, and optimisations to make our users more delighted and engaged on the platform
Run online AB tests and analyse them against the critical business KPIs
Collaborate with US engineering teams as well as cross-functional teams to translate business requirements into technical specifications
Nurture our ML ecosystem to make it withstand scale, developer velocity and future business shifts
Provide technical leadership to drive technical and ML roadmap for search ranking and monetisation
Help in recruiting new engineers. Interview, train, and mentor new team members



We're excited if you have
8+ years of experience (or PhD with 6 years of experience) applying Machine Learning to concrete problems at large-scale in domains like recommendation or search or ads
Strong CS fundamentals. Should be able covert ideas to code with ease
Good understanding of machine learning fundamentals like classification, deep neural nets, and sequence-based models. Familiarity with modern NLP stack and multi-modal representation learning is a plus
We'd love to see that you've worked with big data systems (Spark, S3, and Airflow) and can program (Java, Scala, or Python)
Good understanding of system architecture. Have experience in big data technologies and streaming architecture, data pipelines, etc.
MS in Computer Science, Statistics, or related field, but a Ph.D. in CS or related fields is preferred
Benefits

Roku is committed to offering a diverse range of benefits as part of our compensation package to support our employees and their families. Our comprehensive benefits include global access to mental health and financial wellness support and resources. Local benefits include statutory and voluntary benefits which may include healthcare (medical, dental, and vision), life, accident, disability, commuter, and retirement options (401(k)/pension). Our employees can take time off work for vacation and other personal reasons to balance their evolving work and life needs. It's important to note that not every benefit is available in all locations or for every role. For details specific to your location, please consult with your recruiter.



The Roku Culture

Roku is a great place for people who want to work in a fast-paced environment where everyone is focused on the company's success rather than their own. We try to surround ourselves with people who are great at their jobs, who are easy to work with, and who keep their egos in check. We appreciate a sense of humor. We believe a fewer number of very talented folks can do more for less cost than a larger number of less talented teams. We're independent thinkers with big ideas who act boldly, move fast and accomplish extraordinary things through collaboration and trust. In short, at Roku you'll be part of a company that's changing how the world watches TV.

We have a unique culture that we

About the Company

With the #1 platform for streaming television in the U.S., Roku wants to revolutionize the way the world watches TV. Our Roku-branded TVs, Roku TV models, Smart Home system, streaming players, audio equipment, and the purpose-built operating system that powers it all can turn any home into a home theater, with seamless integration of hardware and software. Our commitment to our users extends to our brand studio, which creates innovative Roku Originals exclusively for The Roku Channel, a free channel that reaches approximat... Know more