Mainframe Performance & Scalability SME

£Open Rate GBP
Hybrid WORKING
Location: Central London, Greater London - United Kingdom Type: Contract
We're looking for a highly experienced Mainframe Performance & Scalability SME to support a short-term consulting assignment, helping assess the resilience, scalability and future performance of a critical enterprise platform.
You'll lead a structured technical investigation into an established IBM mainframe environment, using evidence-based analysis to identify performance constraints, optimisation opportunities and future scalability risks.
This is not a traditional BAU support role - you'll be working as a trusted technical advisor, collaborating with senior architects and engineering teams to deliver meaningful recommendations that influence future technology decisions.
Key Responsibilities

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

About You
You'll have extensive experience across:

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

Consulting Skills
Alongside deep technical expertise, you'll be comfortable with:

• Leading technical discussions with architects, engineers and senior stakeholders.
• Challenging assumptions and validating findings through evidence.
• Turning complex technical analysis into clear, actionable recommendations.
• Working independently within a consulting environment.
• Communicating effectively with both technical and non-technical audiences.

If you're interested in discussing this further, feel free to reach out.