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# Principal Machine Learning Scientist - Search and Recommendations

- **Company:** Expedia Inc.
- **Location:** Seattle, WA, United States
- **Experience:** Expert
- **Salary:** $224,000.0 - $313,500.0
- **Contract:** Permanent contract
- **Skills:** A/B Testing, Artificial Intelligence, Algorithm Design, Amazon Web Services, Microsoft Azure, Big Data, Cloud Computing, Distributed Systems, Apache Hadoop, Python (Programming Language), Machine Learning, Open Source Technology, Recommender Systems, Tensorflow, Reinforcement Learning, Google Cloud, Pytorch, Apache Spark, Deep Learning, Information Technology, Machine Learning Operations
- **Published:** October 22, 2026
- **Apply:** https://www.careerbuilder.com/job-details/principal-machine-learning-scientist-search-and-recommendations-seattle-wa--9f8ad505-2e53-472e-839b-d9aaa3b60028

## About the Role

Machine Learning, Willing to Travel, Advertising, Consumer Branding, Travel Industry, Business-to-Business (B2B), Technical Leadership, Machine Learning, Deep Learning, Artificial Intelligence (AI), * PhD, or MS, in Computer Science, Machine Learning, Statistics, Engineering, or a related field; or equivalent professional experience

 * 10+ years of related industry experience
 * Experience building production-grade search, recommendation or personalization systems
 * Strong understanding of intent understanding techniques, retrieval methods, deep learning for recommendations, reinforcement learning, and causal inference
 * Proficiency in Python and ML frameworks such as TensorFlow, JAX, or PyTorch
 * Experience with large-scale distributed systems and big data technologies (e.g., Spark, Hadoop)
 * Familiarity with A/B testing and experimentation methodologies
 * Ability to work with large-scale, real-world data with attention to bias, fairness, and privacy
 * ·Excellent communication skills for both technical and non-technical audiences
 * Demonstrated ability to mentor and technically lead research or engineering teams
 * A passion for building user-centric AI products and a keen curiosity about advancing the state-of-the-art in search and recommendations, * Experience in the travel or e-commerce industry
 * Familiarity with cloud platforms (AWS, GCP, Azure)
 * Publications in top-tier ML conferences or journals
 * Contributions to open-source ML projects
 * Experience in personalization systems
 * Experience taking models from prototype to production in collaboration with Machine Learning Engineering teams

## Description

* Architect hybrid multi-modal retrieval frameworks, combining text, image, and structured data to power relevant and diverse content discovery
 * Develop and optimize multi-stage ranking pipelines, leveraging deep learning, generative retrieval, and other advanced algorithms to maximize relevance and engagement
 * Lead efforts on intent understanding, utilizing user queries, behavioral signals, and context for superior search and recommendation accuracy
 * Advance personalization strategies using embeddings, user-item modeling, and context-aware algorithms to tailor content to individual users
 * Pioneer cutting-edge sequential recommender systems that account for evolving user preferences, session context, and temporal dynamics
 * Design robust offline and online evaluation methodologies, including A/B testing, counterfactual estimation, and metric development
 * Collaborate closely with cross-functional engineering and product teams to translate business needs into machine learning problems and production-ready solutions
 * Mentor and guide a team of scientists, driving best-in-class research and deployment practices