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