Senior Machine Learning Scientist - CRM Marketing

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.

We create and deliver tailored marketing strategies for Expedia Group's brands, focusing on establishing strong connections and cohesive experiences for travelers and partners. We leverage our functional expertise and creative excellence to build trust and loyalty for our brands through innovative marketing approaches and technology. This role is part of a focused machine learning science team within Marketing that builds the ML systems behind personalized CRM offers for Expedia Group's travelers.

Our models determine which customers to reach, when to engage them, and what incentive to offer - powering retention, reactivation, and growth campaigns that touch hundreds of millions of travelers worldwide. We continuously improve the algorithms that power campaign targeting - moving toward fully ML-driven personalization at scale - and this role will help define that technical roadmap.

• Help define the ML science roadmap:
  Identify the highest-impact ML opportunities for CRM personalization, sequence initiatives against business strategy, and translate a multi-year vision into concrete, deliverable projects with clear milestones and measurable outcomes.
• Build and own production ML systems:
  Lead the full lifecycle — from problem framing and metric design through data exploration, modeling, evaluation, deployment, and iteration — for systems that run daily at scale, in partnership with engineering.
• Partner across the business:
  Work with marketing to understand customer and campaign objectives, with analytics to shape measurement strategies, and with engineering to deliver reliable production systems — bringing business acumen and domain depth to every technical decision.
• Evolve experimentation and measurement:
  Strengthen how we test hypotheses and quantify impact — finding smarter, faster ways to validate ideas, reduce uncertainty, and build confidence in ML-driven decisions before and after they reach production.
• Tell the data story:
  Communicate findings, trade-offs, and recommendations clearly to technical and business audiences through effective data visualization and narratives that influence priorities and build stakeholder confidence.
• Raise the bar:
  Mentor scientists through code reviews and design discussions, drive adoption of modern AI tools and best practices, and champion standards for scientific rigor, reproducibility, and documentation.

• A Master's or PhD in Operations Research, Applied Mathematics, Statistics, Economics, Computer Science, or a related quantitative field; or equivalent related professional experience 6+ years (Master's) or 4+ years (PhD) of experience applying machine learning to real-world problems, with a track record of delivering production ML systems that created measurable business impact
• Proficiency across core ML methods (supervised, unsupervised, and statistical modeling) with demonstrated depth in at least one area relevant to this role
• Strong experimentation and statistics fundamentals: designing rigorous experiments (A/B and beyond), selecting appropriate methods, and producing reliable, accurate analyses that inform high-stakes business decisions
• Fluency in Python, SQL, and distributed data processing (Spark/Databricks), solid software engineering practices, and familiarity with modern AI development tools
• Leader of cross-functional ML projects — aligning…