Job Title: Mainframe Developer – CICS / z/OS Location: London, UK (Hybrid) Experience: 5 Years Employment Type: Contract Job Description Infosys is seeking an experienced Mainframe Developer with strong expertise in IBM Mainframe technologies, including CICS, z/OS, COBOL, JCL, DB2, IMS, and VSAM, to support enterprise-critical banking and financial applications. The candidate will work on development, enhancement, maintenance, and modernization of legacy mainframe systems while ensuring system stability, scalability, and performance. Key Responsibilities Develop, maintain, and enhance applications on IBM z/OS platform Design and code programs using COBOL, JCL, CICS, DB2, IMS, and VSAM Support both online (CICS) and batch processing environments Perform debugging, root cause analysis, and resolution of production issues/abends Optimize SQL queries and DB2 performance tuning Work with schedulers such as Control-M / CA7 / TWS Participate in application modernization initiatives including API enablement and cloud integration Collaborate with business analysts, testers, architects, and offshore teams Follow Agile/Scrum methodology and CI/CD practices Required Skills Strong hands-on experience with: IBM Mainframe / z/OS CICS Transaction Server COBOL, JCL DB2 / IMS VSAM MQ Series Experience with tools: Endevor / ChangeMan File-AID Expeditor / Xpediter Abend-AID SDSF / SPUFI / QMF Strong troubleshooting and performance tuning skills Experience in production support and incident management