Senior Mainframe Systems Administrator (z/OS & IBM series)

About the Role

We’re hiring a seasoned Mainframe Administrator to safeguard the stability, performance, and resilience of our enterprise platforms. You will own the day‑to‑day health of IBM z/OS and AS/400 (IBM iSeries) environments—monitoring capacity, tuning systems, enforcing security, and coordinating changes that keep the business running. The role combines hands‑on administration with cross‑team collaboration, incident response, and—when needed—mentoring others to uplift mainframe skills across the group.

What You’ll Do

• Run the platform: Administer and optimize IBM z/OS and AS/400 (IBM iSeries) systems to maintain uptime, throughput, and predictable performance.
• Monitor & tune: Execute proactive monitoring, capacity planning, and performance tuning across CPU, memory, storage, and I/O.
• Protect the estate: Manage backup/restore routines, DR/BCP playbooks, and high‑availability configurations; regularly test failov...