Java Backend Developer

Position: Java Backend Developer

Client: Walmart

Location: Sunnyvale, CA (On-site / Hybrid)

Engagement Type: Contract

About The Role Walmart's Global Tech hub in Sunnyvale, CA is looking for a talented Java Backend Developer to design and build robust, scalable backend systems that power one of the world's largest retail ecosystems. You will work alongside world-class engineers to architect and deliver high-throughput, fault-tolerant services that handle massive transaction volumes across Walmart's digital and in-store platforms.

Key Responsibilities

• Design, develop, and maintain high-performance Java-based backend services and microservices for enterprise-scale applications.
• Architect and implement RESTful APIs consumed by web, mobile, and internal service clients.
• Apply strong knowledge of data structures and algorithms to solve complex engineering problems efficiently.
• Lead and participate in system design discussions, translating business requirements into scalable, maintainable technical solutions.
• Build and manage microservices architectures using frameworks such as Spring Boot and Spring Cloud.
• Ensure high availability, fault tolerance, and performance optimization across distributed systems.
• Conduct thorough code reviews, mentor junior developers, and uphold engineering best practices.
• Collaborate with frontend teams, data engineers, DevOps, and product managers in an Agile environment.
• Contribute to CI/CD pipeline improvements, automated testing, and deployment strategies.
• Monitor system health, diagnose bottlenecks, and implement proactive performance tuning.

Required Skills & Experience

• 9 years of professional backend development experience with strong expertise in Java (Java 11+).
• Deep understanding of Data Structures and Algorithms — ability to design and analyze solutions for time and space complexity.
• Strong System Design skills — experience designing large-scale distributed systems, including caching strategies, load balancing, database sharding, and message queuing.
• Hands-on experience building and deploying Microservices — service discovery, circuit breakers, API gateways, and event-driven communication.
• Proficiency designing and consuming REST APIs — versioning, authentication (OAuth2/JWT), rate limiting, and documentation (Swagger/OpenAPI).
• Experience with Spring Boot, Spring MVC, Spring Security, and related frameworks.
• Strong working knowledge of relational databases (MySQL, PostgreSQL) and NoSQL databases (Cassandra, MongoDB, or Redis).
• Familiarity with messaging platforms such as Kafka or RabbitMQ.
• Proficiency with Git, Maven/Gradle, and standard SDLC tooling.
• Experience with containerization using Docker and orchestration via Kubernetes.

Preferred / Nice-to-Have Skills

• Experience working with cloud platforms — AWS, GCP, or Azure — in a production environment.
• Familiarity with GraphQL or gRPC as alternatives to REST.
• Exposure to large-scale retail, e-commerce, or fintech backend systems.
• Knowledge of observability tooling — Prometheus, Grafana, Splunk, or Datadog.
• Experience with infrastructure-as-code tools such as Terraform or Helm.
• Understanding of security best practices in distributed systems.

Educational Qualifications

• Bachelor's or Master's degree in Computer Science, Software Engineering, or a related field, or equivalent hands-on experience.