Senior Mainframe Developer (zOS)

ITTConnect • Columbus, OH

1d • Onsite

About The Position

ITTConnect is seeking a Senior Mainframe Developer (zOS Environment) 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) The Senior Mainframe Developer will support a critical legacy platform (MACSS) within a large-scale modernization initiative. This role is key to stabilizing and enhancing the core mainframe applications while enabling integration with modern API and event-driven platforms. You will play a pivotal role in supporting production systems, delivering enhancements, and ensuring seamless integration with z/OS Connect-based services as part of a broader digital transformation program. Why This Role Matters This position is critical in enabling the organization’s transition to a modern, API-driven architecture by ensuring the stability and scalability of its core legacy systems.

Requirements

• 8+ years of hands-on mainframe development experience 

• Strong expertise in: COBOL JCL DB2 CICS
• Proven experience supporting production systems and critical applications
• Experience working in large enterprise environments (preferably utilities, banking, or insurance)
• Strong debugging and problem-solving skills in complex legacy environments

Nice To Haves

• Utilities industry experience.
• Experience with IBM z/OS Connect
• Exposure to API enablement of mainframe systems
• Familiarity with event-driven architectures (Kafka or similar)
• Experience supporting systems undergoing modernization or digital transformation.

Responsibilities

• Own and support a core mainframe application (MACSS) across production, enhancements, and project initiatives
• Develop and maintain applications using COBOL, JCL, DB2, and CICS
• Troubleshoot and resolve production issues across batch and online systems
• Collaborate with API and platform teams to enable integration via z/OS Connect services
• Support data flows and service exposure to downstream platforms ( APIM, Kafka , etc.)
• Participate in system design discussions to support modernization and integration efforts
• Ensure performance, reliability, and scalability of legacy systems

What This Job Offers

• Career Level: Mid Level
• Education Level: No Education Listed