Senior Machine Learning Engineer (Search)

Join Roku's Entertainment Assistant team as a Senior Machine Learning Engineer. In this role, you will lead the development of large-scale ML systems that optimize for multiple objectives, including user engagement, long-term retention, satisfaction, and monetization. You will drive innovation in conversational discovery, contextual recommendations, and personalized content experiences across the platform. The position requires strong technical leadership, product intuition, and the ability to balance user experience with business impact.

• Lead the development of large-scale machine learning systems that optimize for multiple objectives, including user engagement, long-term retention, satisfaction, and monetization.
• Drive innovation in conversational discovery, contextual recommendations, and personalized content experiences across the platform by developing and deploying state-of-the-art ML models.
• Architect scalable machine learning systems, feature platforms, and data pipelines supporting rapid experimentation and long-term growth, while mentoring engineers and providing technical leadership.
• Experience with distributed systems and ML infrastructure such as Spark, Airflow, streaming systems, feature stores, and cloud platforms
• Strong product intuition and experience optimizing user engagement, retention, and monetization simultaneously
• Experience building large-scale ML systems leveraging deep learning, sequence models, LLMs, reinforcement learning, or bandit frameworks
• 8+ years of industry experience (or PhD with 5+ years) applying ML at scale in search, recommendation, ads, personalization, or related domains
• Proficiency in Python, Java, or Scala
• MS or PhD in Computer Science, Statistics, or a related field
• Strong technical leadership, system design, communication, and problem-solving skills
• Strong expertise in ranking systems, recommendation systems, retrieval, personalization, and multi-objective optimization