iSeries (AS/400) Infrastructure Administrator – L3

About the role

We are looking for a senior iSeries (AS/400) Infrastructure Administrator (L3) to lead the administration, optimisation and modernisation of enterprise i environments. The role is the highest level of technical escalation, responsible for performance tuning, security, backup, high‑availability and disaster‑recovery across critical business platforms.

Key responsibilities

• Provide technical leadership and mentorship to L1 Operators and L2 Administrators.
• Develop and enforce operational procedures, standards and best practices for iSeries administration.
• Analyse system performance, conduct capacity planning and produce executive‑level availability reports.
• Design, implement and maintain iSeries security policies, SSL/Digital certificates, SSH keys and support audit compliance.
• Manage backup schedules, troubleshoot BRMS issues and define recovery strategies aligned with business requirements.
• Design, test and operate High‑Availability and Disaster‑Recovery environments meeting RPO/RTO targets.
• Administer internal and external storage, perform disk balancing, performance tuning and IFS management.
• Configure and troubleshoot TCP/IP networking for iSeries servers, HMCs and tape libraries.
• Administer Advanced Job Scheduler, design job‑scheduling strategies and oversee tape‑library lifecycle.
• Plan and execute OS upgrades, PTF management and support application deployments across i partitions.
• Install, configure and manage Hardware Management Consoles (HMC).

Required profile

• 11+ years of experience in iSeries (AS/400) system administration.
• Proven ability to lead technical teams and act as a senior escalation point.
• Strong analytical skills for performance optimisation and capacity planning.
• Experience with security administration, audit support and vulnerability remediation.
• Hands‑on experience with backup/recovery solutions, HA/DR design and testing.
• Excellent documentation and communication skills for executive reporting.

Required skills

• iSeries (AS/400) operating system
• Hardware Management Console (HMC)
• Backup, Recovery and Media Services (BRMS)
• High‑Availability (HA) and Disaster‑Recovery (DR) concepts
• SSL/TLS certificates, Digital certificates, SSH security
• Advanced Job Scheduler
• Integrated File System (IFS) administration
• TCP/IP networking on iSeries platforms
• Storage administration, disk balancing and performance tuning
• PTF management and OS upgrade procedures