Principal Machine Learning Scientist – Search and Personalization

Expedia Group

. Drive research, design, and deployment of advanced machine learning solutions for large-scale search and recommendation systems .

Posted 10/20/2026full-timeUnited StatesLead💰 $224,000 - $387,000 per yearWebsite

Core Competencies

Role fit

Core Competencies

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Expertise in developing and deploying advanced machine learning solutions for search and recommendation systems, with a strong focus on intent understanding, personalization strategies, and evaluation methodologies. Proven ability to lead teams and collaborate across engineering and product domains to translate business needs into effective machine learning applications.

Highest-signal resume keywords

PhD Or MS In Computer Science10+ Years Of Industry ExperienceProficiency In Python And ML FrameworksExperience With Large-Scale Distributed SystemsStrong Understanding Of Intent Understanding Techniques

ATS Keywords

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Applicant Tracking System Keywords

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Hard Skills

Machine LearningDeep LearningGenerative RetrievalReinforcement LearningCausal InferenceMulti-Stage Ranking PipelinesPersonalization SystemsA/B TestingMetric DevelopmentUser-Item Modeling

Soft Skills

Excellent Communication SkillsMentoring And Leadership

Tools & Technologies

TensorFlowJAXPyTorchSparkHadoopAWSGCPAzure

Industry Keywords

Search SystemsRecommendation SystemsE-CommerceTravel IndustryUser-Centric AI Products

Tech Stack

Tools & technologies

AWSAzureCloudDistributed SystemsGoogle Cloud PlatformHadoopPythonPyTorchSparkTensorflow

About the role

Key responsibilities & impact

Drive 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
Develop and optimize multi-stage ranking pipelines using deep learning, generative retrieval, and advanced algorithms
Lead intent understanding efforts using user queries, behavioral signals, and context
Advance personalization strategies using embeddings, user-item modeling, and context-aware algorithms
Pioneer sequential recommender systems accounting for evolving user preferences, session context, and temporal dynamics
Design offline and online evaluation methodologies, including A/B testing, counterfactual estimation, and metric development
Collaborate with engineering and product teams to translate business needs into machine learning problems and production-ready solutions
Mentor and guide a team of scientists and drive research and deployment practices

Requirements

What you’ll need

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 such as Spark and 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 technical and non-technical audiences
Demonstrated ability to mentor and technically lead research or engineering teams
Passion for building user-centric AI products and curiosity about advancing search and recommendations
Experience in the travel or e-commerce industry
Familiarity with cloud platforms such as AWS, GCP, and 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 with Machine Learning Engineering teams

Benefits

Comp & perks

Medical, dental, and vision coverage
Paid time off
Employee Assistance Program
Wellness and travel reimbursement
Travel discounts
International Airlines Travel Agent Network (IATAN) membership