Java Full stack Engineer

Job Description: Job Title: Java Full stack Engineer Job Location: Parsippany, NJ (Onsite) Must Have Technical/Functional Skills 6+ years of hands-on full stack development experience; strong proficiency in Java with Spring Boot for backend microservices development — this is the primary backend stack for the migration program Solid frontend development skills in React.js or Angular — ability to build responsive, accessible web UIs that replace legacy mainframe screens and green-screen interfaces end users currently interact with Strong REST API design and development skills — ability to design clean, versioned, well-documented APIs that serve as the interface between the new cloud platform and frontend applications Hands-on experience with AWS cloud services used in migration programs — EC2, Lambda, API Gateway, RDS/Aurora, DynamoDB, S3, SQS, SNS, Cognito — and understanding of when to use each Proficiency in SQL for relational databases; experience working with both relational (RDS/Aurora, PostgreSQL) and NoSQL (DynamoDB) databases in cloud-native application design Experience with microservices architecture patterns — service decomposition, event-driven design, API-first development, and 12-factor application principles for cloud-native workloads Familiarity with containerization using Docker and deployment via AWS ECS or EKS (Kubernetes) — understanding of how to package, deploy, and manage services in containers Hands-on CI/CD experience — building and maintaining pipelines using Jenkins, GitHub Actions, or AWS CodePipeline for automated build, test, and deployment across environments Experience with unit testing and integration testing frameworks — JUnit, Mockito, Jest, or React Testing Library — and commitment to maintaining meaningful test coverage Ability to understand legacy mainframe data structures and business logic (with SME guidance) and translate them into equivalent cloud-native application behavior — the core skill of this migration program Roles & Responsibilities Build the cloud-native replacement applications that take over the business functions currently running on the mainframe — this is the core job; each engineer owns specific modules from design through deployment Develop backend microservices using Java and Spring Boot that implement business logic equivalent to existing COBOL programs — working closely with SMEs to understand what the legacy code does and ensuring the new service does it correctly Build frontend web UIs using React.js or Angular that replace legacy mainframe screens — designing workflows that are intuitive for business users who are transitioning from character-based interfaces Design and build REST APIs that expose migrated business functionality — ensure APIs are secure, versioned, documented in OpenAPI/Swagger, and aligned with the integration contracts agreed with other workstream teams Integrate new services with AWS managed services — RDS/Aurora for relational data, DynamoDB for high-throughput use cases, SQS/SNS for async messaging, and Lambda for serverless processing Work with the Data Engineer to consume migrated data from AWS target stores — understand source data mappings, validate data in the new schema, and ensure application behavior is correct against migrated datasets Write comprehensive unit and integration tests for all delivered code — not as an afterthought but as part of the Definition of Done for every story Participate actively in all sprint ceremonies — daily stand-up, sprint planning, backlog refinement, and retrospective — with clear daily updates and early escalation of technical blockers Conduct and receive peer code reviews — enforce team coding standards, flag design issues, and treat every review as both a quality gate and a learning opportunity Maintain technical documentation as a sprint deliverable — API specs, data flow diagrams, deployment notes, and known issues — so the program does not accumulate undocumented knowledge debt