Machine Learning Scientist III

Expedia Group brands power global travel for everyone, everywhere. We design cutting‑edge tech to make travel smoother and more memorable, and we create groundbreaking solutions for our partners. Our diverse, vibrant, and welcoming community is essential in driving our success.

To shape the future of travel, people must come first. Guided by our Values and Leadership Agreements, we foster an open culture where everyone belongs, differences are celebrated and we know that when one of us wins, we all win.

We provide a full benefits package, including exciting travel perks, generous time‑off, parental leave, a flexible work model (with some pretty cool offices), and career development resources, all to fuel our employees' passion for travel and ensure a rewarding career journey. We’re building a more open world. Join us.

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.

• Design, develop, and apply machine learning, statistical, and optimisation 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 product ionise 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.

• 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…