Mainframe ZOS System Programmer

About the role

The Mainframe z/OS System Programmer is responsible for the installation, customization, maintenance, and optimization of IBM z/OS operating systems and associated system software. This role ensures the stability, performance, security, and availability of mission-critical mainframe environments, supporting large-scale enterprise applications.

Responsibilities

• System Administration & Maintenance: Install, configure, and maintain IBM z/OS operating systems. Perform system upgrades, migrations (e.g., z/OS version upgrades), and apply maintenance (PTFs, APARs, RSUs). Manage IPL processes, system initialization, and configuration (PARMLIB, PROCLIB, SYS1 datasets). Monitor system health and performance using tools such as RMF, SMF, SDSF.
• Subsystem Support: Install, configure, and support key subsystems: JES2/JES3TSO/E, ISPFUSS (Unix System Services), RACF (in coordination with security teams). Work closely with DB2, CICS, IMS, MQ, and Storage teams for integration and support.
• Performance & Capacity Management: Analyze system performance metrics and implement tuning improvements. Support capacity planning and resource optimization (CPU, memory, I/O). Evaluate hardware upgrades (e.g., CPU/MIPS growth, z-series enhancements).
• Problem Management & Troubleshooting: Diagnose and resolve system-related issues, including system abends and failures. Perform root cause analysis for outages and major incidents. Work with IBM and vendors on problem determination and fixes.
• Automation & Scheduling: Develop and maintain automation using tools such as: System REXX, CLIST, z/OS, NetView. Support job scheduling tools (e.g., CA7, Control-M where applicable).
• Security & Compliance: Support system-level security configurations aligned with RACF policies. Ensure compliance with audit, regulatory, and enterprise security standards. Assist in vulnerability remediation and patching activities.
• Change & Release Management: Execute changes through ITIL-based processes (ServiceNow or equivalent). Prepare implementation plans, backout procedures, and validation steps. Support weekend maintenance windows and IPL activities.
• Documentation: Create and maintain technical documentation, including: System configurations, Standard Operating Procedures (SOPs), Disaster Recovery plans.

Requirements

• 5+ years of experience in mainframe system programming (z/OS).
• Strong hands-on knowledge of z/OS, JES2/JES3, TSO/ISPF, SDSF, USS/OMVS, SMP/E.
• Experience with large-scale environments (multi-LPAR, Parallel Sysplex).
• Knowledge of vendor products (Broadcom, IBM, BMC).
• IBM certifications (preferred but not mandatory).

Preferred Experience

• Exposure to mainframe modernization initiatives (APIs, hybrid cloud integration).
• Experience with z/OSMF and modern interfaces.
• Knowledge of DevOps practices on mainframe (CI/CD pipelines).
• Exposure to Zowe and APIs on z/OS.