• Install, customize, and maintain z/OS and related IBM subsystems. • Manage SMP/E, system upgrades, patching, and maintenance cycles. • Configure system parameters, parmlib members, exits, and JES2/JES3 environments. • Support and tune core components such as VTAM, TCP/IP, RACF, DB2, CICS, IMS, MQ, or equivalent. • Troubleshoot subsystem performance, availability, and integration issues. • Maintain catalog structures, storage classes, and data management utilities. • Analyze system performance, capacity, and utilization trends. • Implement automation tools and procedures to improve operational efficiency. • Support IPL processes, disaster recovery testing, and system cloning activities. • Troubleshoot complex system issues across hardware, OS, and middleware layers. • Collaborate with application, network, and security teams to ensure end‑to‑end stability. • Maintain documentation, standards, and operational runbooks.