Mainframe ZOS System Programmer

Kelly; Phoenix (AZ); On-site; USD 120,000 - 150,000; Full time

Job summary

Kelly is seeking a Mainframe z/OS System Programmer to install, configure, and maintain IBM z/OS environments in the Phoenix area. The role requires onsite work three days a week and welcomes candidates willing to relocate to the area.

You will collaborate with DB2, CICS, IMS, MQ, and storage teams to ensure stability, performance, and security of mission-critical systems. Responsibilities include upgrades, migrations, IPL management, and system tuning.

Qualifications

• Experience administering IBM z/OS and related subsystems.
• Familiarity with RACF security and mainframe integration.
• Proven ability to optimize performance and capacity in large environments.

Responsibilities

• Install, configure, and maintain IBM z/OS operating systems.
• Perform system upgrades and migrations (z/OS versions) with PTFs and APARs.
• Manage IPL processes, PARMLIB, PROCLIB, SYS1 datasets.
• Monitor system health and performance using RMF and SMF.

Skills

z/OS

Mainframe

System programming

Performance tuning

RACF security

Education

Bachelor’s degree in Computer Science

Tools

RMF

SDSF

CA7

Control-M

Job description

* This role requires employees to live in or around the Phoenix, AZ area. You will be responsible to be onsite 3 days a week. We will consider candidates who are willing to relocate to the area.

The Mainframe z/OS System Programmeris 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/JES3
• TSO/E, ISPF
• USS (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).
• 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
• 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: