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.

Why Join Us?

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 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.

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 If you need assistance with any part of the application or recruiting process due to a disability, or other physical or mental health conditions, please reach out to our Recruiting Accommodations Team through the Accommodation Request.

We are proud to be named as a Best Place to Work on Glassdoor in 2024 and be recognized for award-winning culture by organizations like Forbes, TIME, Disability:IN, and others.

Expedia Group's family of brands includes: Brand Expedia®, Hotels.com®, Expedia® Partner Solutions, Vrbo®, trivago®, Orbitz®, Travelocity®, Hotwire®, Wotif®, ebookers®, CheapTickets®, Expedia Group™ Media Solutions, Expedia Local Expert®, CarRentals.com™, and Expedia Cruises™. © 2024 Expedia, Inc. All rights reserved. Trademarks and logos are the property of their respective owners. CST: 2029030-50

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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.