Cambridge, United Kingdom
Open 6 months, first seen by us 205 days agoApply deep learning, bandits, transformers and LLMs to search ranking
Run online A/B tests and analyse results against key business KPIs
Translate business requirements into technical specs with US and cross-functional teams
Lead the technical and ML roadmap for search ranking and monetisation
Interview, train and mentor new engineers on the team
Apply state of the art ML on search using techniques in deep learning, bandits, transformers, LLMs, causal inference, and optimisations
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
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
What experience would help someone be successful in this role at Roku? - 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 to convert ideas to code with ease
- Demonstrated AI/agentic-tooling fluency per the section above - MS in Computer Science, Statistics, or related field, but a Ph.D. in CS or related fields is preferred #LI-MS3
Open 6 monthsWe first saw this posting 205 days ago and it is still up. Roles open this long are often slow to fill or kept open to collect applications.
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Day 205
Up longer than most. Similar jobs usually come down between day 6 and day 70.
Well past Roku’s usual: its jobs come down by about day 97.
From 4,495 similar postings that came down, and 50 of Roku’s. Coming down is not always a hire.
6 open jobs
Open jobs by the week we first saw them, last 12 weeks.
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- 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.
Complete your application on www.weareroku.com. The employer’s form will show what is required.
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New ML Engineer postings at the employers we follow are up 12% over the last 5 weeks compared with the 5 before.
Each bar is one week of new postings. The darkest bars are the last 5 weeks.
Counted from the hiring pages we’ve followed for at least five weeks, so employers we add don’t look like growth. Updated weekly.
We file this job under ML Engineer, by the work the posting describes.
ML engineers put machine learning models into products. They write the code that trains, ships, serves and monitors models so a recommendation or prediction works for real users.
Postings ask for strong Python and software engineering, a framework such as PyTorch, cloud services, and more and more often experience with large language models.
A data scientist often works out which model to build; an ML engineer makes it run reliably in production.
The government has no code for ML engineers, so these figures are for the closest group, computer and information research scientists.
Source: US Bureau of Labor Statistics, Occupational Employment and Wage Statistics (May 2025) and Employment Projections (2025 to 2035). Occupation code 15-1221.
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.
Roku is the No. 1 TV streaming platform in the U.S., Canada, and Mexico with 70+ million active accounts. Roku pioneered streaming to the TV and continues to innovate and lead the industry. The depth of query, content, and user understanding using ML is key to user happiness on the search and discovery journey, and this team owns the models that power it across the Roku platform.
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. 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.
At Roku, we don’t just use AI, we work with it. AI agents and smart tools help power drafts, analysis, and repetitive workflows, while our people bring direction, judgment, and accountability. We’re looking for curious, adaptable builders who can show how they’ve used AI or automation to move faster, raise the bar, and scale their impact.
We value your AI skills if you have built fluency across the agentic engineering toolchain — coding harnesses like Claude Code or Cursor, MCP servers, custom skills, or agent frameworks. And you can describe projects where you shipped real work with these tools. You know how to drive an agent, verify its output, and ramp on an unfamiliar codebase with an agent helping you.
Roku fosters an inclusive and collaborative environment where teams generally work in the office Monday through Thursday. Fridays are generally flexible for remote work, except for employees whose specific roles or assigned office location require five days' a week attendance.
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). Employees are supported in taking time off, in accordance with local leave policies and other personal needs to support 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.
Roku welcomes applicants of all backgrounds and provides reasonable accommodations and adjustments in accordance with applicable law. If you require reasonable accommodation at any point in the hiring process, please direct your inquiries to EmployeeRelations@Roku.com.
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 are proud of. We think of ourselves primarily as problem-solvers, which itself is a two-part idea. We come up with the solution, but the solution isn't real until it is built and delivered to the customer. That penchant for action gives us a pragmatic approach to innovation, one that has served us well since 2002.
To learn more about Roku, our global footprint, and how we've grown, visit https://www.weareroku.com/factsheet.
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Cambridge, United Kingdom
#LI-MS3 What's Roku's approach to hybrid working? Roku fosters an inclusive and collaborative environment where teams generally work in the office Monday through Thursday. Fridays are generally flexible for remote work, except for employees whose specific roles or assigned office location require five days' a week attendance. What are some of the benefits?
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