Senior, Data Scientist

Position Summary...

What you'll do...

Walmart Global Tech is seeking a highly skilled and experienced Senior Data Scientist to join our Personalization and Recommendation team. This role will be instrumental in driving forward Walmart’s personalization capabilities across multiple touchpoints — from product recommendations and layout optimization to GenAI-powered customer understanding. The ideal candidate combines deep ML expertise with large-scale production experience and thrives in fast-paced, impact-driven environments. 

As part of our team, you’ll join a fast-paced and collaborative environment that blends research with real-world impact. You’ll work closely with world-class engineers, product managers, and fellow scientists to push the boundaries of what personalization means in modern retail — crafting solutions that are fair, relevant, and truly customer-centric at a global scale.

About Team:
Our team works closely with our US stores and eCommerce business to better serve customers by empowering team members, stores, and merchants with technological innovation. From groceries and entertainment to sporting goods and crafts, Walmart U.S. offers an extensive selection that our customers value, whether they shop online at Walmart.com, through one of our mobile apps, or in-store. Focus areas include customers, stores and employees, in-store service, merchant tools, merchant data science, and search and personalization.

What you'll do:

• Design, develop, and productionalize machine learning models for personalized recommendations, layout optimization, and content generation (visual and textual) using structured and unstructured data.
• Lead the development of large-scale ML models leveraging deep learning (Transformers, multi-modal, LLMs), reinforcement learning, and personalization frameworks (e.g., agentic systems).
• Collaborate cross-functionally with engineering, product, and design teams to integrate ML systems into customer-facing applications.
• Build scalable data pipelines and feature stores with data engineers for real-time and batch personalization use cases.
• Employ and experiment with pre-trained foundation models (e.g., BERT, RoBERTa, T5, CLIP) for customer representation and product understanding.
• Apply best-in-class practices in model validation, monitoring, explainability (e.g., SHAP, counterfactuals), and lifecycle management.
• Contribute to research and innovation in personalization by exploring novel architectures and publishing internally or externally where applicable.

What you'll bring:

• Have a MS/PhD in relevant technical degree (preferably Computer Science, Machine Learning, Operations Research, Applied Mathematics, Statistics, Engineering etc.) with 2-4 years of relevant work experience.
• Proven experience developing and deploying ML models at scale in a production environment, especially for recommendation systems, ranking, or NLP tasks.
• Proficiency in Python, SQL, and PySpark. Strong familiarity with ML libraries such as TensorFlow, PyTorch, Scikit-Learn, XGBoost.
• Strong knowledge of ML evaluation and diagnostic techniques (A/B testing, ROC-AUC, Precision@K, RMSE, etc.).
• Experience with foundation models and LLMs
• Background in reinforcement learning or agent-based personalization frameworks.
• Experience working with big data tools (Hive, Spark) and modern MLOps practices.

About Walmart Global Tech
Imagine working in an environment where one line of code can make life easier for hundreds of millions of people. That’s what we do at Walmart Global Tech. We’re a team of software engineers, data scientists, cybersecurity expert's and service professionals within the world’s leading retailer who make an epic impact and are at the forefront of the next retail disruption. People are why we innovate, and people power our innovations. We are people-led and tech-empowered. We train our team in the skillsets of the future and bring in experts like you to help us grow. We have roles for those chasing their first opportunity as well as those looking for the opportunity that will define their career. Here, you can kickstart a great career in tech, gain new skills and experience for virtually every industry, or leverage your expertise to innovate at scale, impact millions and reimagine the future of