Senior Developer – IBM z/OS Connect

ITTConnect is seeking a Senior Mainframe Developer - IBM zOS Connect to work on site for a client in the Columbus, OH area. This is a contract position with a client that is a global leader in consulting, digital transformation, technology and engineering services with over 300,000 team members in nearly 50 countries. The end client is in the Utilities sector.

Job location : Columbus, OH or Nashville, TN (both locations would be for on site work)

We are seeking a Senior Developer with strong expertise in IBM z/OS Connect to support Gigawatt.ai modernization initiatives by designing and building new z/OS-based services integrated with MACSS (legacy utility management mainframe application). This role focuses on exposing mainframe capabilities as modern APIs and enabling seamless enterprise integration.

Key Responsibilities :

• Design, develop, and deploy RESTful APIs using IBM z/OS Connect


• Build and expose mainframe services (CICS, IMS, DB2) to distributed systems


• Integrate z/OS services with MACSS and other enterprise platforms


• Translate business requirements into scalable API-based solutions


• Ensure performance, security, and reliability of z/OS services


• Collaborate with cross-functional teams (middleware, integration, application teams)


• Troubleshoot and resolve issues across z/OS and API layers


• Support modernization initiatives by enabling API-driven mainframe access
  

Requirements

• Strong hands-on experience with IBM z/OS Connect (EE preferred)


• Solid background in z/OS environment (CICS, IMS, DB2)


• Experience building and consuming REST APIs


• Knowledge of JSON, OpenAPI/Swagger


• Familiarity with mainframe integration patterns


• Strong debugging and performance tuning skills on z/OS


• Experience working in enterprise, high-availability environments

Nice to Have:

• Experience with API management tools (e.g., IBM API Connect)


• Exposure to middleware/integration platforms


• Understanding of security protocols (OAuth, JWT, RACF)


• Prior experience with legacy system modernization initiatives