Senior .NET Full Stack Engineer - IBM i / iSeries / AS400

TJX Companies

At TJX Companies, every day brings new opportunities for growth, exploration, and achievement. You’ll be part of our vibrant team that embraces diversity, fosters collaboration, and prioritizes your development. Whether you’re working in our four global Home Offices, Distribution Centers or Retail Stores—TJ Maxx, Marshalls, Homegoods, Homesense, Sierra, Winners, and TK Maxx, you’ll find abundant opportunities to learn, thrive, and make an impact. Come join our TJX family—a Fortune 100 company and the world’s leading off-price retailer.

Job Description:Senior .NET Full Stack Engineer - IBM i / iSeries / AS400**
About the RoleWe’re looking for an experienced Senior Full Stack Engineer** to help support and modernise our E-commerce Fulfilment technology landscape.

This role requires experience working with IBM i / iSeries / AS400 applications, along with strong modern engineering skills in C#, .NET, REST APIs, front-end technologies and Microsoft Azure.

You will work across both the existing and future technology landscape, supporting and enhancing critical IBM i applications while helping progressively modernise capabilities using modern services, cloud technologies and engineering practices.

What You’ll Do

• Develop a strong understanding of the existing IBM i / AS400 application landscape, including business processes, integrations, operational workflows and embedded business logic.
• Work with RPG, CL and DB2 applications, contributing to enhancements, defect resolution, troubleshooting and production support.
• Provide backup and contingency support for critical IBM i applications and help ensure continuity of existing business capabilities.
• Capture and document critical application logic, dependencies and support processes, working with SMEs to retain and transfer legacy knowledge and reduce key-person dependency.
• Design, develop, test and deploy modern applications using C#, .NET, REST APIs, front-end technologies and Microsoft Azure.
• Modernise existing capabilities by translating IBM i workflows, business rules, integrations and data into scalable and maintainable modern services and applications.
• Build APIs, integrations and cloud capabilities using secure engineering, automated testing and CI/CD practices.
• Troubleshoot and perform root-cause analysis across IBM i, integration and modern application layers.
• Collaborate with Product, Architecture, Operations and Engineering teams to support current applications while shaping future solutions.