Senior Machine Learning Engineer

Accepting Applications Until 25 September 2026 Job Description Your New Role **: Senior Machine Learning Engineer Global’s Data team is looking for a Senior Machine Learning Engineer to build, deploy and scale machine learning solutions—turning data science ideas into robust, production-grade products. As a Senior Machine Learning Engineer at Global, you’ll support use cases across DAX, our digital ad exchange—such as the cross-device audience identity graph and real-time targeting algorithms. You’ll join a high-performing, cross-functional DAX squad of data engineers, product specialists and analytics experts, helping build and evolve our cutting-edge ad-serving technology for audio and Outdoor. This is a hybrid role based at our Holborn office in central London. Key Responsibilities** * Model Development \& Optimisation: Design, build and optimise ML and deep-learning models—including for ad targeting and attribution—with a focus on scalability, performance and accuracy, and prototype and evaluate new approaches. * ML Pipelines \& Real-Time Inference: Build and maintain robust end-to-end ML pipelines covering training, validation, deployment and monitoring, and develop real-time inference systems with low latency and high throughput. * Monitoring \& Reliability: Implement model monitoring, drift detection, alerting and retraining, and optimise models for reliability and cost efficiency in AWS. * Collaboration \& Enablement: Partner with data engineers to integrate ML workflows into wider platforms (Spark, Databricks), and share best practice and mentor other technical professionals. What You’ll Love About This Role * Think Big: Build ML and AI solutions that shape products, improve decision-making and unlock growth. * Own It: Take ideas from concept to production and see the impact of your work in the real world. * Keep it Simple: Turn complex technical challenges into scalable, practical solutions. * Better Together: Work with smart, supportive people across data, engineering, analytics and the wider business. **What Success Looks Like In Your First Few Months, You’ll Have** * Built ML products that deliver measurable value, improving Global’s capabilities in areas such as ad targeting and attribution. * Ensured ML models are reliably deployed, monitored and maintained, with automated, reproducible and scalable pipelines. * Built real-time systems that operate efficiently and reliably under production demand. * Developed a strong understanding of Global’s data ecosystem, tools and operating model, particularly within DAX. **What You’ll Need** * Production ML experience: You’ve delivered ML and deep-learning projects at high data volume commercially, owning deployment, CI/CD, monitoring and lifecycle management. * Strong Python: Solid Python with PyTorch or similar ML frameworks. * Model evaluation: You diagnose why models underperform across data, features and architecture, and make reasoned trade-offs. * Real-time \& distributed ML: A strong grasp of production inference patterns, plus Spark and distributed data processing. * Reproducibility \& tooling: Reproducible environments (UV/Docker) and MLflow or equivalent, on AWS with Spark, Databricks and Snowflake. * Engineering mindset: A focus on reliability, maintainability and continuous improvement.