Senior Mainframe Test Lead (z/VSE to z/OS Migration)

About the role

NTT DATA's Client is seeking an experienced Senior Mainframe Test Lead (z/VSE to z/OS Migration) to lead the end-to-end testing strategy, planning, governance, and execution for a large-scale z/VSE to z/OS migration program.

Responsibilities

• Define and own the overall migration testing strategy, framework, and roadmap.
• Establish testing standards, quality gates, entry/exit criteria, and governance processes.
• Develop a risk-based testing methodology aligned to migration waves and cutover milestones.
• Provide executive reporting on testing progress, quality metrics, risks, and release readiness.
• Lead application and infrastructure impact assessments to understand migration-related changes.
• Establish a risk-ranking model to classify components as High, Medium, or Low Risk based on: Code modifications, JCL conversion impacts, Data migration changes, CICS transaction changes, Interface dependencies, Security changes, Operational and scheduler impacts, Business criticality.
• Design testing depth and coverage based on migration risk and business impact.
• Maintain a Testing Risk Register and Migration Testing Heat Map.
• Identify migration-specific risks and ensure mitigation plans are incorporated into testing activities.
• Develop comprehensive testing plans covering: System Testing, System Integration Testing (SIT), End-to-End Business Process Testing, Regression Testing, Data Validation & Reconciliation Testing, Performance & Volume Testing, User Acceptance Testing (UAT), Cutover & Rollback Validation Testing.
• Define testing coverage for: COBOL applications, CICS transactions, JCL conversion and batch processing, VSAM, DB2, and IMS databases, File transfers and interfaces, Security configurations and access controls, Enterprise schedulers, Infrastructure and operational procedures.
• Validate functional equivalence and operational readiness of workloads migrated to z/OS.
• Ensure proper reconciliation of converted data and migrated business processes.
• Coordinate testing across: Mainframe Teams, Application Teams, Infrastructure Teams, Security Teams, Database Teams, Business SMEs.
• Lead defect triage, prioritization, and remediation activities.
• Drive issue resolution and dependency management across teams.
• Define cutover rehearsal and mock migration testing strategies.
• Validate production deployment procedures and rollback capabilities.
• Ensure all critical business processes are successfully executed during rehearsal events.
• Provide Go/No-Go recommendations for migration releases.

Qualifications

• Mandatory Mainframe Experience: 10+ years of experience in Test Architecture, Test Management, or Quality Engineering.
• Strong hands-on knowledge of Mainframe applications, platforms, and testing methodologies.
• Experience with: z/VSE, z/OS, COBOL, CICS, JCL, VSAM, DB2 and/or IMS, RACF / ACF2 / Top Secret, Batch Processing, Enterprise Scheduling tools.
• Demonstrated experience leading testing for Mainframe modernization, platform upgrades, rehosting, or z/VSE-to-z/OS migration initiatives.
• Risk-Based Testing Expertise: Proven experience implementing risk-based testing methodologies within complex transformation programs, strong ability to conduct migration impact assessments and translate findings into targeted testing strategies, experience identifying and prioritizing testing scope based on technical, business, operational, and compliance risks, ability to balance test coverage, quality, and program timelines through intelligent risk management.
• Leadership & Communication: Experience leading large, cross-functional testing organizations, strong stakeholder management skills across business and technology teams, exceptional executive communication and governance reporting capabilities, deliverables include: Enterprise Test Strategy, Risk-Based Testing Framework, Migration Test Plan, Test Coverage Matrix, Impact Assessment & Risk Heat Map, Environment & Test Data Strategy, SIT and End-to-End Test Plans, Defect Management Process, Cutover Rehearsal Plan, Go/No-Go Readiness Assessments, Executive Quality Dashboards.