Machine Learning Scientist III

At Expedia Group, we help travelers explore the world, one journey at a time. As a global travel company powered by passionate people, trusted partnerships, and leading technology, we connect travelers, partners, and advertisers through our consumer brands, B2B network, and travel advertising business. Here, you'll do meaningful work that helps millions of people discover, book, and experience travel with more ease, confidence, and joy. Our five Behaviors-Traveler First, Think Big, Operate with Excellence, Ownership Mindset, and Succeed Together-help foster a supportive environment where people can grow their careers and have the flexibility, benefits, and support to do their best work. Join us and build for travelers everywhere. The EG Advertising Machine Learning team sits at the heart of Expedia Group’s global advertising marketplace—a fast-growing, high-impact business at the intersection of travel, technology, and commerce. The team develops the predictive models that power our platform, including click-through rate and booking propensity models, as well as deeper insights into advertiser bidding behaviour and broader marketplace dynamics. It’s a unique environment where machine learning directly shapes real-time auctions, personalised experiences, and large-scale optimisation across a complex two-sided ecosystem. As a Machine Learning Scientist III, you’ll play a key role within this team, applying machine learning to connect millions of travellers with thousands of partners. One of the most exciting aspects of the role is the end-to-end visibility across both auction and personalisation systems, allowing you to drive meaningful, system-wide impact rather than focusing on a single component. Working closely with product and engineering partners, you’ll combine deep data exploration with strong business context to design and deliver scalable, production-ready solutions that directly influence user experience and marketplace performance. In this role, you will: Design, develop, and apply machine learning, statistical, and optimization models to solve business problems in EG Advertising, including predictive modelling for ad auction systems (e.g., click-through rate, booking propensity, and advertiser bidding dynamics), improving both partner and traveller outcomes. Translate ambiguous business questions into measurable scientific problems, defining success metrics and delivering data-driven recommendations grounded in experimentation, deep data exploration, and marketplace understanding. Partner closely with engineers, product managers, analysts, and business stakeholders to productionize models, influence roadmap decisions, and drive adoption of ML-powered solutions across both partner-facing and traveller-facing systems. Build and evaluate scalable approaches across multiple technical domains, including feature engineering, model development, experimentation design (A/B testing), data modelling, and integration into production services within large-scale distributed systems. Safely integrate and operate AI/ML-enabled solutions that improve outcomes, including applying modern ML techniques and selective use of GenAI/agentic AI approaches to enhance modelling, experimentation, and system capabilities. Contribute strong technical judgment through documentation, code reviews, model monitoring, and operational best practices that support reliable, scalable, and reusable scientific solutions across the advertising marketplace. Minimum Qualifications: Advanced degree (MS or PhD) in Machine Learning, Computer Science, Statistics, Applied Mathematics, Economics, or a related field. 5+ years of relevant industry experience applying machine learning, statistical modelling, experimentation, or optimisation techniques in production environments. Demonstrated ownership of end-to-end machine learning solutions at the service, multi-service, or domain level, with accountability for model quality, business impact, and operational reliability. Strong technical foundation in machine learning methods, experimental design (A/B testing), data analysis, and programming for production-quality solutions working with large-scale datasets. Proficiency in Python and its ML/data ecosystem (e.g., PySpark, pandas, TensorFlow, PyTorch or similar) and strong SQL skills. Experience partnering cross-functionally to frame problems, communicate trade-offs, and deliver solutions from ideation through production. Strong first-principles problem-solving skills and ability to clearly communicate complex technical concepts. Demonstrated strength in architecture and design of ML systems, including data modelling, experimentation frameworks, and production integration patterns. Preferred Qualifications: Experience building and scaling machine learning systems for advertising, ranking, recommendation, auction optimisation, pricing, or forecasting. Experience working in or a strong understanding of two-sided marketplaces, online advertising, or e-commerce ecosystems. Experience using data and model insights to influence product strategy and business decisions. Hands-on exposure to GenAI, LLMs, or AI-driven tooling that supports faster experimentation, improved modelling, or better product outcomes. Accommodation requests Expedia Group is committed to providing an inclusive and accessible recruiting experience. If you need an accommodation or adjustment due to a disability during the application or recruiting process, please submit a request at . About Expedia Group Expedia Group includes three flagship consumer brands - Expedia, , and Vrbo - along with a leading B2B travel business and travel advertising offerings. Across our brands and business, we help travelers explore the world with confidence and ease. Important notice Employment opportunities and job offers at Expedia Group will always come from Expedia Group's Talent Acquisition and hiring teams. Never share sensitive personal information unless you are confident of the recipient. Expedia Group does not extend job offers via email or messaging tools to individuals with whom we have not made prior contact. Our email domain is @expediagroup.com. The official place to find and apply for roles is . Equal Opportunity Expedia is committed to creating an inclusive work environment with a diverse workforce. All qualified applicants will receive consideration for employment without regard to race, religion, gender, sexual orientation, national origin, disability or age.