Senior Machine Learning Engineer

About the Team

The Recommendations team drives personalized experiences across our platform by leveraging state-of-the-art machine learning. Our mission is to deliver meaningful, context-aware recommendations that adapt to each user's preferences in real time. We believe that true innovation in personalization requires more than great models—it depends on a robust, flexible ML platform built for experimentation and scale. To that end, we design and build the underlying ML infrastructure, ensuring our systems remain fast, reliable, and at the forefront of technology. Our work blends innovation, engineering excellence, and a deep commitment to understanding our users, shaping how they discover and engage with content every day.

About the Role

We seek an outstanding, creative, and passionate Machine Learning Platform Engineer to join Roku's Recommendation team. In this role, you will design, build, and scale robust distributed systems that power the next generation of personalized content recommendations for millions of Roku users. You will develop end-to-end machine learning platforms and infrastructure, ensuring seamless deployment, monitoring, and optimization of algorithms and operational workflows that deliver unique experiences at scale.

What You'll Be Doing

• Design, build, and maintain scalable platform services: feature store, real-time inference services, vector DBs, etc., that serve millions of transactions per second
• Run and monitor online AB tests via robust platform services, analyzing platform metrics and business KPIs to optimize recommendation system performance
• Collaborate closely with US-based engineering and cross-functional teams to translate business requirements into modular platform components and APIs
• Enhance and evolve the ML platform ecosystem to support high developer velocity, system scalability, and adaptability to future business needs
• Contribute to onboarding, training, and mentoring new team members on emerging platform engineering best practices and technologies

We’re Excited If You Have

• 5+ years of experience building software solutions to concrete problems
• Strong CS fundamentals. Should be able to write an algorithm with ease
• You are fluent with one of the high-level programming languages like Java, Scala, Kotlin, or Python
• We’d love to see that you’ve worked with big data systems (Spark, Kafka, Flink, S3, AirFlow)
• Familiar with model ML frameworks and tools: Ray, PyTorch, HuggingFace, AWS Sagemaker
• AI literacy and curiosity. You have either tried Gen AI in your previous work or outside of work, or are curious about Gen AI and have explored it.
• MS in Computer Science or related field