Senior Mainframe Performance & Scalability Expert

Arm; City Of London; Hybrid; GBP 111,000 - 166,000; Full time

Job summary

Arm is seeking a senior Mainframe Performance & Scalability SME to support a focused assessment for a major UK financial services client. The role focuses on Db2, CICS, and mainframe capacity, with an emphasis on diagnosing scalability risk from production evidence and leading client conversations with architects and operations SMEs.

The assignment covers Db2 estate analysis, potential refactoring, observability improvements, and capacity planning across IBM Z platforms.

Qualifications

• Experience with Db2 for z/OS performance and scalability in an enterprise environment.
• Ability to diagnose scalability risk from production evidence and lead technical discussions with client architects.
• Strong understanding of CICS, Db2, and mainframe capacity management in large-scale systems.
• Experience with observability tooling and interpreting CPU/MSU/I/O metrics to drive remediation.

Responsibilities

• Lead technical conversations with client architects and operations SMEs to assess scalability risk.
• Analyze Db2, CICS and workload performance to identify remediation paths.
• Evaluate TLS/cryptography impact and infrastructure changes for performance.
• Produce actionable recommendations and clear evidence-based justification for improvements.

Skills

Db2 for z/OS performance

CICS performance

Mainframe capacity planning

RMF/SMF analysis

TLS / IBM Z cryptography

Observability & diagnostics

Tools

OMEGAMON

MainView

BMC AMI

RMF

SMF

Datadog

Job description

Arm is seeking a senior Mainframe Performance & Scalability SME to support a focused assessment for a major UK financial services client. The role focuses on Db2, CICS, and mainframe capacity, with an emphasis on diagnosing scalability risk from production evidence and leading client conversations with architects and operations SMEs.

The assignment covers Db2 estate analysis, potential refactoring, observability improvements, and capacity planning across IBM Z platforms.