IBM Mainframe Infrastructure Subject Matter Expert

Salary: £54,000 - 72,000 per year

Requirements

• Strong experience with IBM Z Series / IBM mainframe infrastructure (Z/OS or above)
• Deep expertise in IBM CICS Transaction Server
• Proficiency in COBOL
• Experience with IBM Db2
• Familiarity with IBM MQ
• Strong background in legacy regulated banking environments
• Infrastructure SME experience (not application development focused)
• Proven ability to support and stabilise production mainframe systems

Responsibilities

• Support IBM Z Series mainframe infrastructure in a live banking environment
• Manage CICS regions (TORs, AORs, FORs)
• Maintain and support IBM CICS Transaction Server environments
• Ensure 24x7 system availability and operational resilience
• Troubleshoot and resolve production incidents
• Work with IBM Db2 and IBM MQ
• Use JCL, REXX, and Assembler for support and diagnostics
• Maintain high stability across core banking transaction systems

Technologies

• COBOL
• IBM
• IBM Db2
• IBM Mainframe
• Support
• Security
• DevOps

More

We are seeking an experienced IBM Mainframe Infrastructure Technical Specialist to support a major UK banking organisation operating on IBM Z Series and above infrastructure. This is a production stability and support SME role, focused on maintaining and optimising a complex legacy mainframe estate within a regulated banking environment. The position offers high remote work flexibility (99% remote), contract security potential within a major financial institution, and the opportunity to significantly impact critical infrastructure systems.

last updated 19 week of 2026