Are you passionate about using machine learning to outsmart fraud and protect travelers without adding friction?
Would you like to work in the fast-paced, adversarial, high-scale, and data-rich world of online travel risk?
The Fraud & Risk team plays a pivotal role in safeguarding the company’s finances, thwarting billions of dollars in fraudulent attacks annually.
Our efforts extend beyond financial security—we effectively combat various threats, including phishing attacks, counterfeit vacation rental schemes, improper payment diversions, and unauthorized access to personal and payment card information.
By ensuring a secure environment, the team fosters trust among travelers and providers, making Expedia’s sustained revenue growth possible.
This is a rare chance to build a simpler, more explainable and adaptive decisioning platform in a live, scaled environment.
We are looking for a hands-on Principal Machine Learning Scientist to help us build and execute on a high visibility, high-impact vision to dramatically improve our auto-prevention rates, reduce ops queuing, and apply novel techniques using Generative AI to the ever-evolving, adversarial world of fraud.

Requirements

Bachelor's, Master's, or Ph.D. degree in a technical field or equivalent related professional experience
Expertise in more than one major ML programming language (Python, R, Scala, etc.) and familiarity with others
Experience leading large data science technical programs, delivering successful outcomes typically involving cross-functional teams of 10+
Demonstrated ability to regularly contribute to the data science and technology community through blog posts, tech talks, major data science or technology domain conferences/events, etc.
Experience defining data science best practices at a team/capability level
Expertise in configuring, maintaining, and optimizing storage and processing environments (cloud, on-premises, cluster management, etc.)
In-depth understanding of all aspects of machine learning theory
Strong experience in application in an industrial setting and crafting robust solutions relatively quickly
Solid theoretical foundation applies advanced statistical methods to a broad range of problems
Experience with advanced methods such as Stochastic Processes, Bayesian Neural Networks, Markov Models, Discriminant and Factor Analysis, and applies them while considering underlying assumptions and limitations
Continuous learning and adaptability to stay ahead of rapidly evolving technologies and techniques in machine learning and data science
Strong communication and storytelling skills to effectively convey complex technical concepts to diverse stakeholders
Collaborative mindset and ability to lead cross-functional teams in delivering innovative solutions
Strategic thinking and business acumen to align machine learning initiatives with organizational goals and drive measurable impact
Ethical and responsible AI practices to ensure fairness, transparency, and accountability in machine learning model development and deployment.

Benefits

medical/dental/vision
paid time off
Employee Assistance Program
wellness & travel reimbursement
travel discounts
International Airlines Travel Agent (IATAN) membership

Applicant Tracking System Keywords

Tip: use these terms in your resume and cover letter to boost ATS matches.

Hard Skills & Tools

machine learningPythonRScaladata science best practicesStochastic ProcessesBayesian Neural NetworksMarkov ModelsDiscriminant AnalysisFactor Analysis

Soft Skills

strong communicationstorytellingcollaborative mindsetstrategic thinkingbusiness acumencontinuous learningadaptabilityleadershipproblem-solvingethical AI practices

Certifications

Bachelor's degreeMaster's degreePh.D. degree