Senior Machine Learning Engineer, Search & Recommendations

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. What does the team work on? 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. What is 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. 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. How will I use AI at Roku? 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. What are the responsibilities of the role? • 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 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 • Good understanding of machine learning fundamentals