Mainframe Performance & Scalability SME

In this contract role you will act as a Mainframe Performance & Scalability SME, leading evidence-based investigations into a large IBM mainframe environment. You’ll collaborate with senior architects and engineering teams to identify constraints, optimise performance and assess future scalability. You’ll translate complex analysis into clear, actionable recommendations that influence technology decisions. This position offers a hands-on consultancy footprint with meaningful impact on enterprise platform resilience.

• Lead investigations into mainframe performance, scalability and capacity
• Analyse Db2 and CICS workloads to identify bottlenecks and optimisation opportunities
• Review SQL performance, access paths, indexing, and data management approaches
• Assess mainframe capacity, workload management, batch processing, and MSU utilisation
• Investigate performance impacts from infrastructure changes (e.g., IBM Z migrations, cryptographic processing)
• Correlate business transactions with application, database, CPU and I/O to identify root causes
• Review monitoring and observability across the platform
• Assess performance testing approaches and validate scalability assumptions
• Produce clear findings and prioritised recommendations for senior technical stakeholders

• IBM Z mainframe environments and performance optimisation
• Db2 for z/OS performance analysis (SQL tuning, access paths, RUNSTATS, REORG, locking, workload behaviour)
• CICS transaction processing and application performance analysis
• Mainframe capacity management (RMF, SMF, WLM, MSU utilisation)
• Batch and online workload analysis for performance constraints and scalability risks
• Mainframe monitoring/diagnostics tooling (OMEGAMON, MainView, BMC AMI, RMF/SMF or equivalent)
• Performance testing, workload modelling and capacity assurance

• Leading technical discussions with architects and engineers
• Challenging assumptions and validating findings with evidence
• Turning complex analysis into clear, actionable recommendations
• Mainframe performance optimisation
• Db2 for z/OS performance analysis
• CICS performance analysis