Senior Machine Learning Engineer - Personalization

Requirements

• You have hands-on experience building recommendation or personalization systems at scale
• You’re comfortable working across the ML stack, including pipelines, backend systems, and infrastructure
• You think in products and understand how model decisions impact user experience
• You’re fluent with AI-assisted development and use it to accelerate experimentation thoughtfully
• You’re curious about emerging approaches like generative models and agentic ML systems
• You’ve taken models from prototype to production and care about reliability and monitoring
• You’re comfortable with ambiguity and enjoy defining new approaches in evolving problem spaces

What You'll Be Doing

• Design, train, and ship machine learning models that power recommendations on the Now Playing View for hundreds of millions of users
• Own ranking systems end-to-end, from experimentation and training pipelines to online serving and monitoring
• Build and iterate on generative and agentic ML approaches to improve session steering and cross-content discovery
• Work in an AI-native development environment, using AI tools to accelerate development while applying strong engineering judgment
• Run A/B experiments, define success metrics, and translate improvements into measurable user impact
• Collaborate closely with engineers, data scientists, researchers, and product managers to bring ideas into production
• Shape the ML roadmap by identifying high-impact opportunities and mentor teammates

Perks and Benefits

• This role is based in London
• We offer you the flexibility to work where you work best! There will be some in-person meetings, but it still allows for flexibility to work from home