Implementation Manager - Mainframe Product Migration

Req ID: 390892 Competitive salary | UK: hybrid: Sheffield OR London + remote At NTT DATA, we know that with the right people on board, anything is possible. The quality, integrity, and commitment of our employees are key factors in our company’s growth, market presence and our ability to help our clients stay a step ahead of the competition. By hiring the best people and helping them grow both professionally and personally, we ensure a bright future for NTT DATA and for the people who work here. NTT DATA is currently looking for an Implementation Manager - Mainframe Product Migration  on a hybrid work model (Sheffield or London + remote) for our growing team in the UK. 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.,…