(USA) Principal, Data Scientist

Walmart • Sunnyvale, CA

7d • Onsite

About The Position

The Principal Data Scientist will lead the design, development, and deployment of AI-powered Search and Personalization systems serving hundreds of millions of customers across Walmart's global eCommerce platforms. This role demands deep expertise in information retrieval, ranking, recommendation systems, and Generative AI applied at production scale. You will define technical strategy, shape ML architecture, and partner with Product and Engineering to turn ambiguous discovery problems into measurable customer and business outcomes, while mentoring a team of senior scientists raising the bar across the discipline.

Walmart's Search & Personalization team shapes how hundreds of customers discover products every day. We sit at the intersection of AI research and global-scale systems, owning query understanding, retrieval, ranking, recommendations, and real-time personalization end to end. We work closely with Ads and Sparky, Walmart's AI shopping assistant, building the science that powers discovery across the full customer journey.

Requirements

• Proven track record in Search, Information Retrieval, Ranking, Recommendations, or Personalization at production scale.
• Hands-on experience with PyTorch and Transformer architectures for relevance modeling, semantic search, or multi-task learning.
• Practical experience applying Generative AI to real products, including RAG, instruction fine-tuning, or RLHF.
• Strong engineering skills in Python and Scala, with experience building large-scale Spark-based ML pipelines.
• Solid command of experimentation: causal inference, A/B testing, interleaving, and offline/online metric alignment.
• Experience operationalizing ML systems at scale, including model serving, drift monitoring, and continuous training.
• Excellent communication skills and ability to lead multi-quarter technical initiatives across cross-functional teams.
• Bachelors degree in Statistics, Economics, Analytics, Mathematics, Computer Science, Information Technology or related field and 5 years' experience in an analytics related field.
• Masters degree in Statistics, Economics, Analytics, Mathematics, Computer Science, Information Technology or related field and 3 years' experience in an analytics related field.
• 7 years' experience in an analytics or related field

Nice To Haves

• Data science, machine learning, optimization models
• PhD in Machine Learning, Computer Science, Information Technology, Operations Research, Statistics, Applied Mathematics, Econometrics
• Publications or active peer reviewer in related journals or conference
• Successful completion of one or more assessments in Python, Spark, Scala, or R
• Using open source frameworks (for example, scikit learn, tensorflow, torch)
• We value candidates with a background in creating inclusive digital experiences, demonstrating knowledge in implementing Web Content Accessibility Guidelines (WCAG) 2.2 AA standards, assistive technologies, and integrating digital accessibility seamlessly.
• The ideal candidate would have knowledge of accessibility best practices and join us as we continue to create accessible products and services following Walmart’s accessibility standards and guidelines for supporting an inclusive culture.

Responsibilities

• Own end-to-end design and delivery of ML systems for Search ranking, query understanding, retrieval, recommendations, and real-time personalization.
• Build and productionize deep learning and Transformer-based models for relevance, intent classification, and semantic matching.
• Apply Generative AI and LLMs, including RAG and fine-tuning, to improve query understanding and product discovery.
• Design large-scale feature engineering and training pipelines handling petabyte-scale catalog and behavioral signals.
• Define experimentation strategies, offline evaluation frameworks, and online/offline metric alignment for Search and P13n systems.
• Drive technical architecture decisions and influence the long-term AI roadmap.
• Mentor senior scientists and establish team standards for model development and production deployment.

Benefits

• Performance-based bonus awards
• Medical coverage
• Vision coverage
• Dental coverage
• 401(k)
• Stock purchase
• Company-paid life insurance
• PTO (including sick leave)
• Parental leave
• Family care leave
• Bereavement
• Jury duty
• Voting
• Short-term disability
• Long-term disability
• Company discounts
• Military Leave Pay
• Adoption and surrogacy expense reimbursement
• PTO and/or PPTO that can be used for vacation, sick leave, holidays, or other purposes.
• Live Better U is a Walmart-paid education benefit program for full-time and part-time associates in Walmart and Sam's Club facilities. Programs range from high school completion to bachelor's degrees, including English Language Learning and short-form certificates. Tuition, books, and fees are completely paid for by Walmart.

What This Job Offers

• Job Type: Full-time
• Career Level: Principal