Senior Mainframe Migration & Cutover Lead

Whitehall Resources; Sheffield; On-site; GBP 80,000 - 110,000; Full time

Job summary

Whitehall Resources is seeking an experienced Mainframe Implementation Manager to plan, coordinate, and execute end-to-end migration of a mainframe product into production, ensuring a controlled, compliant, and low-risk cutover. Own the deployment and governance across technology, operations, business, and third parties.

You will lead integrated cutover plans, drive readiness, coordinate CAB and change activities, manage data migration, rehearse dress runs, and report on progress to senior

Qualifications

• Proven track record in Implementation/Cutover/Deployment management on large-scale mainframe migrations.
• Experience with z/OS production operations constraints and batch scheduling.
• Experience running dress rehearsals, coordinating cross-team cutovers, and leading go/no-go forums.
• Familiarity with ITIL-aligned change, release, and incident management in regulated environments.

Responsibilities

• Create and maintain the integrated implementation (deployment/cutover) strategy and plan covering scope, approach (big bang/phased), timeline, dependencies, and critical path.
• Lead cutover planning: detailed runbooks, rehearsal plans, roles/responsibilities, communications, checkpoints, and contingency/rollback.
• Coordinate release and change management activities (CAB submissions, implementation approvals, change records, stakeholder signoffs).
• Drive environment and operational readiness: capacity, access, monitoring, scheduling/batch windows, support model, service transition.
• Manage data migration implementation activities with clear sequencing, validation steps, reconciliation, and operational controls.
• Orchestrate dress rehearsals / mock cutovers, capture lessons learned and harden runbooks.
• Lead implementation governance: readiness reviews, RAID management, decision logs, and executive reporting.
• Coordinate hyper care/post-go-live: incident triage, defect backlog prioritisation, stabilisation metrics, and handover to BAU.
• Ensure alignment with risk/compliance/audit requirements (evidence packs, approvals, segregation of duties where required).
• Manage third parties/vendors involved in deployment (e.g., infrastructure, platform, data, app support, schedulers).
• Implementation strategy and Integrated Cutover Plan
• Detailed cutover runbooks (minute-by-minute where needed)
• Rehearsal plans and rehearsal outcomes/actions log
• Change/CAB artefacts and approval pack
• Readiness criteria, go/no-go checklist, and decision log
• Hypercare plan, support model, and BAU handover pack
• Implementation closure report and lessons learned

Skills

Leadership

Stakeholder management

Governance

ITIL awareness

Change management

Tools

z/OS

JCL

Control-M/CA-7

DB2/IMS

CICS

Job description

Whitehall Resources is seeking an experienced Mainframe Implementation Manager to plan, coordinate, and execute end-to-end migration of a mainframe product into production, ensuring a controlled, compliant, and low-risk cutover. Own the deployment and governance across technology, operations, business, and third parties.

You will lead integrated cutover plans, drive readiness, coordinate CAB and change activities, manage data migration, rehearse dress runs, and report on progress to senior