Senior Machine Learning Scientist

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 know that when one of us wins, we all win.

We’re looking for a Senior Machine Learning Scientist to provide technical leadership within our Search Marketing & Tech organization at Expedia Group. This role is for someone who has demonstrated a track record of delivering high-impact ML projects from concept through production, partnering closely with engineering teams on multi-quarter initiatives that drive measurable business outcomes.

Our team builds and optimizes the ML models that power metasearch bidding and auction strategies across key partners (Google Hotel Ads, Trivago, Tripadvisor). As a senior technical leader, you will own end-to-end ML solutions for a domain area, define the technical roadmap, and drive the execution of complex projects that improve customer experiences and business performance at scale.

In this role, you will:

• Own end-to-end ML solutions within your domain, from problem framing and metric design through data exploration, model development, deployment, and post-launch iteration
• Define technical direction for your area, including model architecture, system design, data contracts, and integration patterns with existing services
• Lead multi-quarter ML initiatives in partnership with engineering, product, and business stakeholders, driving projects from ambiguous requirements to production systems at scale
• Author technical blueprints and system designs that clearly outline objectives, constraints and trade-offs for complex ML systems

• Design and implement production-grade ML models (e.g., gradient-boosted trees, deep learning, optimization algorithms, bandits/RL policies) that operate reliably under real-world constraints in collaboration with engineering.
• Build robust training, evaluation, and serving pipelines with embedded observability, drift detection, and failure handling across the ML lifecycle
• Enhance experimentation and measurement strategies, including A/B tests, causal inference methods, and long-horizon metrics to ensure models deliver durable impact as data and user behavior evolve

• Partner with engineering teams to translate ML designs into scalable, maintainable production systems, ensuring alignment on timelines, dependencies, and technical standards
• Influence domain roadmaps by connecting ML opportunities to business objectives, articulating trade-offs, and building stakeholder alignment through evidence-based recommendations
• Translate ambiguous business problems into clear ML formulations with measurable success criteria, balancing technical feasibility with business impact
• Lead structured reviews with cross-functional partners, presenting complex technical concepts and trade-offs to both technical and non-technical audiences

• Raise the technical bar for the broader science community by codifying best practices, experimentation standards, and reusable patterns
• Mentor other data and machine learning scientists, providing technical guidance through code reviews, design discussions, and knowledge sharing
• Drive adoption of AI best practices

• Master’s or PhD in Computer Science, Statistics, Applied Mathematics, Operations Research, or related quantitative field, or equivalent industry experience
• 6+ years (Master’s) or 4+ years (PhD) of hands‑on experience applying machine learning to real‑world problems
• Demonstrated track record of leading at least one complex, multi‑stakeholder production ML initiative that delivered measurable business impact

• Deep ML expertise in…