Senior Machine Learning Engineer

Salary: £60,000 - 100,000 per year

Requirements

• Senior-level ML engineering experience, ideally with exposure to ad tech, recommendation, or auction systems
• Strong grounding in machine learning fundamentals, feature engineering, and model evaluation
• Experience with Spark, Python, and Java in production ML settings
• Comfort with production ML infrastructure and real-time, low-latency serving requirements
• Demonstrated fluency with AI and agentic engineering tools
• Clear communication skills with the ability to explain reasoning and trade-offs

Responsibilities

• Design, train, and ship ML models for ad relevance and bid/yield optimization
• Build and maintain production ML infrastructure for real-time, low-latency serving
• Work across Spark, Python, and Java to move models from research to production
• Apply sound feature engineering, validation, and evaluation practices throughout the modelling lifecycle
• Diagnose production ML issues such as model drift or long-tail classification problems
• Communicate technical trade-offs clearly to engineering and cross-functional partners

Technologies

• AI
• Support
• Java
• Machine Learning
• Python
• Roku
• Spark
• AI Agents
• Claude Code
• Cursor
• LESS
• MCP

More

We are Roku, the #1 TV streaming platform in the U.S., Canada, and Mexico, and we pioneered streaming to the TV. Our mission is to connect the entire TV ecosystem by helping consumers find the content they love, enabling publishers to build and monetize audiences, and giving advertisers unique ways to engage consumers at scale. You will join Praveen Krishnaiahs Native Ads Modelling team, working on the ML systems behind ad relevance, bid and yield optimization, and real-time ad serving. This is a senior, hands-on role based in the UK, with a Manchester-anchored setup. We offer a fast-paced, collaborative environment, generally work in the office Monday through Thursday with flexible remote work on Fridays, and provide a broad range of benefits including mental health and financial wellness support, statutory and voluntary benefits, leave policies, and local healthcare and retirement options where available.

last updated 34 week of 2026