Mainframe Implementation Manager
Whitehall Resources currently require an experienced Mainframe Implementation Manager to work with a key client.
**Please note this role falls INSIDE IR35**
Role purpose: Plan, coordinate, and execute the end-to-end implementation of a mainframe product migration into production, ensuring a controlled, compliant, and low-risk cutover. Own the integrated deployment/cutover plan, readiness, and go/no-go governance across technology, operations, business, and third parties.
Key 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).
Deliverables (typical)
- 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
Required experience
- Proven Implementation/Cutover/Deployment Management on mainframe or large-scale legacy migrations.
- Strong understanding of z/OS production operations constraints: batch cycles (JCL), scheduling (e.g., Control-M/CA-7), DB2/IMS considerations, CICS regions, interface dependencies, and resilience/DR practices.
- Experience running dress rehearsals, coordinating cross-team cutovers, and leading go/no-go forums.
- Working knowledge of ITIL-aligned change, release, and incident management in regulated environments.
All of our opportunities require that applicants are eligible to work in the specified country/location, unless otherwise stated in the job description.
Whitehall Resources are an equal opportunities employer who value a diverse and inclusive working environment. All qualified applicants will receive consideration for employment without regard to race, religion, gender identity or expression, sexual orientation, national origin, pregnancy, disability, age, veteran status, or other characteristics.