Mainframe Middleware Infra Engineer – CICS Liberty

Role: Mainframe Middleware Infra Engineer – CICS Liberty

Location: London/Edinburgh

Type of Job: Contract

Mode of work: Hybrid -2-3 days onsite in week

JD:

Key Responsibilities

•CICS & z/OS Systems Engineering Expertise – Individual must display deep practical experience with how CICS runs on z/OS, beyond application development.

•IBM WebSphere Liberty (CICS Liberty) & Java Runtime Skills - A CICS Liberty Infrastructure Engineer must understand Liberty as a runtime and have experience in configuring the runtime

•Security, Integration & Modern Ops Practices - CICS Liberty environments are exposed to modern integration patterns and strict security requirements.

Essential skills/knowledge/experience:

•             CICS system setup and configuration (regions, JVM servers)

•             Understanding of z/OS components used by CICS Liberty (USS, RACF, TCP/IP, SMF)

•             Capacity planning, performance tuning, and availability (HA/DR)

•             Problem determination using dumps, traces, SMF data, and logs

•             WebSphere Liberty configuration (server.xml, features, shared libraries)

•             JVM tuning for z/OS (heap sizing, GC behaviour)

•             Managing Java workload inside CICS (JVM servers lifecycle, diagnostics)

•             Patching and maintaining Liberty and Java SDK levels

•             RACF and TLS configuration (certificates, keyrings, SAF integration)

•             REST/HTTP exposure and API enablement

•             CI/CD awareness (bundles, pipelines, automated deployment)

•             Operational monitoring and log management