Mainframe Middleware Infrastructure Engineer

Job in Greater London, London, Greater London, W1B, England, UK

Listing for: Sivara GmbH

Contract position
Listed on 2026-06-21

Job specializations:

IT/Tech
Systems Engineer, SRE/Site Reliability, Cloud Computing: Infrastructure & Operations, IT Infrastructure

Salary/Wage Range or Industry Benchmark: 36000 - 60000 GBP Yearly GBP 36000.00 60000.00 YEAR

Location: Greater London

Salary: £36,000 - 60,000 per year

Requirements

Deep knowledge of CICS systems engineering and z/OS infrastructure
Experience with CICS region setup, configuration, and JVM server management
Strong knowledge of IBM Web Sphere Liberty administration and runtime configuration
Experience managing Java workloads, including JVM tuning and performance optimisation
Working knowledge of RACF, TLS, certificates, keyrings, and security integration
Experience with REST/API enablement and modern integration practices
Ability to perform problem determination using dumps, traces, logs, and SMF data
Experience with capacity planning, resilience, HA/DR, and operational support
Experience with CI/CD pipelines, automated deployments, and release processes
Knowledge of monitoring, observability, and middleware operational management

Responsibilities

Support the engineering, configuration, optimisation, and support of modern Java workloads running within CICS Liberty environments
Manage CICS region setup, configuration, and JVM server operations
Administer IBM Web Sphere Liberty runtime environments
Tune JVM performance and manage Java workloads
Implement and support REST/API enablement and modern integration practices
Investigate and resolve issues using dumps, traces, logs, and SMF data
Support capacity planning, resilience, HA/DR, and operational stability
Work with CI/CD pipelines, automated deployments, and release processes
Contribute to monitoring, observability, and middleware operational management

Technologies

API
CI/CD
IBM
IBM Web Sphere
Support
JVM
Java
REST
Security
Websphere
Dev Ops

We are offering a 6-12 month contract for a Mainframe Middleware Infrastructure Engineer (CICS Liberty) based in London or Edinburgh with a hybrid working model of 2-3 days onsite. This is an excellent opportunity to work on critical banking and financial services infrastructure while helping modernise core mainframe platforms with contemporary Java and API technologies. We are seeking someone to join a major enterprise transformation programme and help support our modernisation efforts.

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