(USA) Senior, Data Scientist

Walmart•Sunnyvale, CA

2d•$117,000 - $234,000

About The Position

The Senior Data Scientist will develop, evaluate, and deploy advanced AI models and algorithms that power Walmart customer and business experiences. The role applies scientific rigor to convert complex customer and business problems into scalable, measurable AI solutions, combining hands-on model development with cross-functional collaboration and influence. Retail AI Foundations, within Walmart’s Retail Intelligence group in the AI & Data organization, develops and deploys generative AI and machine learning platforms, models, and services for growth areas including AI Shopping, Social Commerce, Walmart Connect advertising, creator experiences, marketing, and rich-media content. Applied Science and ML Engineering teams build capabilities in large language models, image and video generation, and multimodal understanding, partnering with scientists, engineers, product managers, and business leaders to improve experiences and deliver measurable outcomes while practicing responsible AI. The Senior Data Scientist will collaborate with ML engineers, product managers, data teams, and business partners to define success measures, build and validate models, and improve production performance. The role also includes communicating technical recommendations and results, and mentoring junior scientists and engineers.

Requirements

Strong hands-on expertise in Python, machine learning, deep learning, NLP, information retrieval, computer vision, multimodal AI, and model evaluation.
Ability to translate customer and business needs into model designs, experiments, technical requirements, and scalable production solutions, and communicate findings and tradeoffs across product, engineering, data, business, and leadership teams.
Experience adapting open-weight models for business use cases through model selection, post-training, fine-tuning, and evaluation, including LLM-, vision-, multimodal-, and agent-based systems.
Experience benchmarking models and participating in A/B tests, and optimizing training and inference architectures for quality, cost, latency, throughput, scalability, and reliability.
Experience with techniques such as prompt optimization, custom loss functions, reasoning models, and test-time scaling.
Experience creating high-quality retail training and evaluation data, including dataset sourcing and curation, unsupervised or weakly supervised learning, synthetic-data approaches, and ground-truth development with crowdsourcing and annotation partners.
Experience with distributed training and inference, large-scale model serving, and massively parallel GPU systems.
Ability to use AI coding assistants effectively and build production agentic AI applications that orchestrate models, tools, and workflows.
Minimum qualification option 1: Bachelor’s degree in Statistics, Economics, Analytics, Mathematics, Computer Science, Information Technology, or a related field and 3 years of experience in an analytics-related field.
Minimum qualification option 2: Master’s degree in Statistics, Economics, Analytics, Mathematics, Computer Science, Information Technology, or a related field and 1 year of experience in an analytics-related field.
Minimum qualification option 3: 5 years of experience in an analytics or related field.

Nice To Haves

4+ years of experience building machine learning models or developing algorithms for business applications.
Master’s or PhD in Computer Science, Electrical Engineering, Machine Learning, Engineering, Robotics, Operations Research, Statistics, Mathematics, or a related quantitative field, or equivalent practical experience.
Experience with LLM post-training and alignment, including supervised fine-tuning, reinforcement learning, RLHF, DPO, or related techniques.
Experience with image or video generation models, multimodal understanding models, or production computer-vision systems.
Experience building, evaluating, and operating LLM- or agent-based systems at production scale.
Data science, machine learning, or optimization-model experience.
Master’s degree in Machine Learning, Computer Science, Information Technology, Operations Research, Statistics, Applied Mathematics, or Econometrics.
Successful completion of one or more assessments in Python, Spark, Scala, or R.
Experience using open-source frameworks such as scikit-learn, TensorFlow, or Torch.
Background in creating inclusive digital experiences, including knowledge of WCAG 2.2 AA standards, assistive technologies, and accessibility best practices.

Responsibilities

Build, evaluate, and improve machine learning and generative AI models across LLMs, image and video generation, multimodal understanding, and agentic systems.
Develop data and evaluation strategies, including dataset curation, exploratory analysis, feature engineering, error analysis, ground truth, and offline evaluation.
Design and execute model experiments, benchmarking, and A/B tests to measure quality, safety, reliability, latency, scalability, and business impact.
Apply post-training, fine-tuning, retrieval, prompting, and other optimization techniques to improve production model performance.
Partner with product, engineering, data, and business teams to translate opportunities into technical requirements, success metrics, and deployable solutions.
Work with ML Engineers to deploy, monitor, and iterate on models in large-scale production environments.
Communicate technical recommendations and model results to stakeholders.
Mentor junior scientists and engineers on rigorous experimentation and responsible AI practices.

Benefits

Competitive pay and performance-based bonus awards.
Medical, vision, and dental coverage.
401(k), stock purchase, and company-paid life insurance.
Paid time off, including sick leave, parental leave, family care leave, bereavement, jury duty, and voting leave.
Short-term and 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, a Walmart-paid education benefit program for eligible full-time and part-time associates, covering tuition, books, and fees for eligible programs.