Principal Machine Learning Scientist (Search and Recommendations)

TL;DR

Principal Machine Learning Scientist (AI/ML): Leading the development and optimization of Expedia’s Search & Recommendation AI models with an accent on natural language search, multi-modal search, and generative AI-based discovery. Focus on architecting hybrid multi-modal retrieval frameworks, optimizing multi-stage ranking pipelines, and advancing personalization strategies.

Location: San Jose, CA, USA

Salary: $242,000 – $338,500

Company

A global travel company connecting travelers, partners, and advertisers through its consumer brands, B2B network, and travel advertising business.

What you will do

• Drive the research, design, and deployment of advanced machine learning solutions for large-scale search and recommendation systems.
• Architect hybrid multi-modal retrieval frameworks combining text, image, and structured data for content discovery.
• Develop and optimize multi-stage ranking pipelines leveraging deep learning and generative retrieval.
• Lead efforts on intent understanding utilizing user queries, behavioral signals, and context.
• Pioneer sequential recommender systems and advanced personalization strategies using embeddings and user-item modeling.
• Mentor and guide a team of scientists while collaborating with cross-functional engineering and product teams.

Requirements

• PhD or MS in Computer Science, Machine Learning, Statistics, Engineering, or equivalent professional experience.
• 10+ years of related industry experience.
• Proven experience building production-grade search, recommendation, or personalization systems.
• Proficiency in Python and ML frameworks such as TensorFlow, JAX, or PyTorch.
• Experience with large-scale distributed systems and big data technologies (Spark, Hadoop).
• Strong understanding of reinforcement learning, causal inference, and A/B testing methodologies.

Nice to have

• Experience in the travel or e-commerce industry.
• Publications in top-tier ML conferences or journals.
• Contributions to open-source ML projects.
• Familiarity with cloud platforms (AWS, GCP, Azure).

Culture & Benefits

• Medical, dental, and vision coverage.
• Paid time off and Employee Assistance Program.
• Wellness and travel reimbursement.
• Travel discounts and International Airlines Travel Agent Network (IATAN) membership.
• Inclusive environment driven by behaviors like Traveler First and Ownership Mindset.