(USA) Principal, Data Scientist

About the role

The Principal Data Scientist will lead the development and deployment of advanced analytical models and machine learning solutions to address complex business challenges. This role requires deep expertise in statistical analysis, AI, and data strategy to translate business needs into scalable, data-driven solutions. The position involves mentoring team members, collaborating cross-functionally, and ensuring the quality and impact of data initiatives. The successful candidate will drive innovation through rigorous testing, model validation, and continuous improvement, supporting Walmart’s commitment to operational excellence and delivering measurable business value.

About the team

Walmart's Search & Personalization team drives how millions of customers find and engage with products daily. Positioned at the intersection of AI research and large-scale systems, the team owns recommendations, real-time personalization, user modeling, ranking, and behavioral intelligence end to end. Collaborating closely with Ads and Sparky, Walmart's AI shopping assistant, the team develops advanced science that delivers tailored shopping experiences throughout the customer journey. This group leverages expertise in machine learning, deep learning, and AI to build innovative solutions that improve customer engagement, conversion, and business outcomes on a global scale.

Responsibilities

• Own end-to-end design and delivery of personalization ML systems spanning recommendations, user modeling, real-time ranking, and personalized product discovery.
• Build and productionize deep learning models for CTR/CVR prediction, sequential recommendation, and user/item representation learning.
• Apply Generative AI and LLMs, including RAG and fine-tuning, to deliver personalized shopping experiences across the customer journey.
• Design large-scale behavioral feature pipelines handling petabyte-scale user interaction signals in Spark and Scala.
• Define experimentation strategies, offline evaluation frameworks, and online/offline metric alignment for P13n systems.
• Drive personalization architecture decisions and influence the long-term AI roadmap.
• Mentor senior scientists and establish team standards for model development and production deployment.

Requirements

• Proven track record building Recommendation Systems, Personalization platforms, or user-facing ranking models at production scale.
• Hands-on experience with PyTorch and Transformer architectures for sequential modeling, user/item embeddings, 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 behavioral signal pipelines.
• Solid command of experimentation: causal inference, A/B testing, interleaving, and offline/online metric alignment for personalization systems.
• Experience operationalizing ML systems at scale, including real-time model serving, drift monitoring, and continuous training.
• Excellent communication skills and ability to lead multi-quarter technical initiatives across cross-functional teams.

Qualifications

Outlined below are the required minimum qualifications for this position. If none are listed, there are no minimum qualifications.

• Option 1: Bachelors degree in Statistics, Economics, Analytics, Mathematics, Computer Science, Information Technology or related field and 5 years' experience in an analytics related field.
• Option 2: Masters degree in Statistics, Economics, Analytics, Mathematics, Computer Science, Information Technology or related field and 3 years' experience in an analytics related field.
• Option 3: 7 years' experience in an analytics or related field.

Preferred Qualifications

Outlined below are the optional preferred qualifications for this position. If none are listed, there are no preferred qualifications.

• 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.

Benefits

• Health benefits: medical, vision and dental coverage.
• Financial benefits: 401(k), stock purchase and company-paid life insurance.
• Paid time off benefits: PTO (including sick leave), parental leave, family care leave, bereavement, jury duty, and voting.
• Other benefits include short-term and long-term disability, company discounts, Military Leave Pay, adoption and surrogacy expense reimbursement, and more.
• Live Better U: Walmart-paid education benefit program for full-time and part-time associates. 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. Eligibility requirements apply to some benefits.

You will also receive PTO and/or PPTO that can be used for vacation, sick leave, holidays, or other purposes. The amount you receive depends on your job classification and length of employment. It will meet or exceed the requirements of paid sick leave laws, where applicable.

Pay

The annual salary range for this position is $143,000.00 - $286,000.00. Additional compensation includes annual or quarterly performance bonuses and stock for certain positions.

Primary location: 1395 Crossman Ave, Sunnyvale, CA 94089-1114, United States of America.