PRINCIPAL, DATA SCIENTIST

Position Summary...

What you'll do...

About Team

The Catalog Data Science Team at Walmart Global Tech advances the state of the art in generative AI (GenAI), artificial intelligence (AI), machine learning (ML), statistics, deep learning, computer vision and optimization to ensure Walmart’s product catalog is accurate, complete and optimized for customer experience. We solve large-scale challenges in product classification, attribute extraction, trust & safety, and catalog optimization—powering next-generation retail experiences for hundreds of millions of customers.

What you'll do:

We are seeking a Principal Machine Learning Engineer to set the technical direction and lead the design of large-scale AI/ML platforms and products. You combine deep hands-on expertise with strategic vision to drive company-wide impact.

As a Principal ML Engineer, you’ll:

* Define and drive the multi-year technical strategy and architecture for catalog AI/ML systems across classification, attribution, trust & safety and generative experiences.
* Architect production-grade GenAI systems including retrieval orchestration, tool/use-case routing, policy engines, and evaluation harnesses.
* Lead the design of training and serving stacks for LLMs and multi-modal models: distributed fine-tuning, parameter-efficient methods, distillation, quantization and compilation.
* Own and improve reliability, latency and cost SLOs for online inference; design autoscaling, caching, batching, and GPU/accelerator utilization strategies.
* Establish platform standards for data quality, lineage, governance and cost management across ML pipelines.
* Build reusable evaluation and observability frameworks (offline metrics, human-in-the-loop, A/B testing, canaries) with robust telemetry and alerting.
* Champion MLOps/LLMOps best practices: CI/CD for models, registries, feature/embedding stores, vector databases, rollout/rollback, shadowing and drift detection.
* Mentor and develop Senior/Staff engineers and scientists; raise the bar on code quality, design reviews, technical writing and operational excellence.
* Influence cross-functional roadmaps and align with Product, Platform, Data Engineering, Security and Infrastructure to deliver outcomes at global scale.
* Publish, file patents and build partnerships with academia/open-source communities; represent Walmart at top-tier AI/ML venues.
* Ensure solutions meet privacy, security, compliance and Responsible AI requirements.
* Architect and lead fine-tuning, distillation and domain adaptation of foundation models (LLMs and vision-language) for retail-specific tasks, including instruction-tuning and RAG.
* Optimize inference at scale using quantization, tensor/pipeline parallelism, speculative decoding, KV-cache management and high-performance serving (e.g., Triton, vLLM, TensorRT-LLM).
* Design rigorous evaluation and safety frameworks for generative systems (LLM-as-judge, red teaming, factuality, bias/fairness, toxicity) and enforce policy through guardrails.

What you'll bring:

* PhD with 7+ years of relevant experience / Master’s with 10+ years / Bachelor’s with 12+ years in Computer Science or a strongly quantitative field.
* Demonstrated leadership delivering multiple large-scale ML/GenAI products in production with measurable business impact.
* Deep expertise in transformer architectures, retrieval-augmented generation, parameter-efficient fine-tuning, model distillation and evaluation.
* Strong programming skills in Python (and optionally C++/Rust) with production experience in PyTorch/TensorFlow/JAX and modern data/streaming frameworks (e.g., Spark, Flink, Kafka).
* Proven experience with distributed training/serving on Kubernetes and cloud environments; familiarity with CUDA/NCCL, sharding/ZeRO, mixed precision and performance profiling.
* Strong grasp of data governance, privacy, security and Responsible AI; experience operationalizing policies and controls.
* Track record of publications or intellectual property generation in top-tier venues.
* Excellent communication, stakeholder management and mentoring skills; high ownership and bias for action.

Good to have:

* Experience with eCommerce domain, product knowledge graphs and taxonomy/attribute systems.

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 retail.

Flexible, hybrid work

We use a hybrid way of working with primary in office presence coupled with an optimal mix of virtual presence. We use our campuses to collaborate and be together in person, as business needs require and for development and networking opportunities. This approach helps us make quicker decisions, remove location barriers across our global team, be more flexible in our personal lives.

Benefits

Beyond our great compensation package, you can receive incentive awards for your performance. Other great perks include a host of best-in-class benefits maternity and parental leave, PTO, health benefits, and much more.

Belonging

We aim to create a culture where every associate feels valued for who they are, rooted in respect for the individual. Our goal is to foster a sense of belonging, to create opportunities for all our associates, customers and suppliers, and to be a Walmart for everyone.

At Walmart, our vision is "everyone included." By fostering a workplace culture where everyone is—and feels—included, everyone wins. Our associates and customers reflect the makeup of all 19 countries where we operate. By making Walmart a welcoming place where all people feel like they belong, we’re able to engage associates, strengthen our business, improve our ability to serve customers, and support the communities where we operate.

Equal Opportunity Employer

Walmart, Inc., is an Equal Opportunities Employer – By Choice. We believe we are best equipped to help our associates, customers and the communities we serve live better when we really know them. That means understanding, respecting and valuing unique styles, experiences, identities, ideas and opinions – while being inclusive of all people.

Minimum Qualifications...

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

Preferred Qualifications...

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

Primary Location...