Principal Software Engineer – Marketplace Platforms

Position Summary... What you'll do...
Role Overview: We are seeking a Principal Software Engineer to lead the design and development of enterprise‑scale Marketplace platforms supporting sellers, listings, pricing, orders, and real‑time transactions. This role requires deep expertise in Java ,
distributed systems ,
event‑driven architectures ,
Kafka , and Big Data ecosystems , with exposure to AI/ML‑driven marketplace intelligence .

Building the right technology foundation for Infrastructure & platforms is vital to success at the scale of Walmart. Our team builds and maintains the foundational technologies that support the tech organization. Included in this are data platforms, enterprise architecture, Dev Ops, cloud computing, and infrastructure. All of these products and services are supported by scalable and powerful infrastructure, ensuring a secure and seamless employee and customer experience across stores, digital channels, and distribution centers.

• You will serve as a technical authority responsible for building high‑throughput, low‑latency systems that power marketplace growth at massive scale.
• Architect and build distributed marketplace services for seller onboarding, catalog, pricing, inventory, and order flows.
• Design event‑driven and streaming architectures using Apache Kafka for real‑time marketplace signals.
• Develop and optimize Java‑based microservices using Spring / Spring Boot.
• Build high‑volume data pipelines using Big Data frameworks (Spark, Hadoop, Flink) for analytics and ML.
• Enable AI/ML use cases such as fraud detection, pricing optimization, seller scoring, and recommendations.
• Lead system design reviews
  , performance tuning, and scalability planning.
• Define engineering standards for resiliency, observability, CI/CD, and operational excellence
  .
• Mentor senior engineers and influence platform‑wide architectural decisions.
• Partner with product, data science, infrastructure, and security teams.

• 10+ years of software engineering experience in large‑scale systems.
• Expert proficiency in Java with strong knowledge of concurrency and multithreading.
• Deep experience building distributed, highly available systems.
• Hands‑on experience with Apache Kafka (topics, partitions, offsets, schema evolution, exactly‑once semantics).
• Experience with Big Data technologies
  :
  • Spark (batch & structured streaming).
  • Hadoop ecosystem (HDFS, Hive, YARN).
  • Flink or equivalent stream‑processing engines.
• Strong experience with microservices
  , REST/gRPC APIs.
• Proficiency with SQL and No
  
  SQL databases (MySQL, Postgre
  
  SQL, Cassandra, Mongo
  
  DB, etc.).
• Strong system design, troubleshooting, and performance‑optimization skills.

• Marketplace, e‑commerce, payments, or supply‑chain platform experience.
• Cloud‑native development on AWS, GCP, or Azure
  .
• Experience with Kubernetes, Docker
  , and service mesh.
• Experience handling millions of sellers, SKUs, and transactions
  .
• Familiarity with ML platforms
  , feature stores, or real‑time inference.
• Experience with observability tools (Prometheus, Grafana, ELK, Open Telemetry).
• Strong understanding of security, data governance, and compliance
  .

• Platforms process millions of marketplace events per minute.
• Systems are fault‑tolerant, scalable, and operationally mature.
• Marketplace data enables real‑time insights and AI‑driven decisions.
• Engineering standards align with enterprise‑scale best practices.

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 experts 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…