We are supporting a fast-paced transformation programme for an established MSP / ISP that is replacing multiple core platforms, including ITSM, Finance, Billing, Sales, Operations and Monitoring.This role is vital to ensuring accurate, validated data migration across legacy and new systems, including migration from ServiceNow to Halo.We are seeking a hands-on, methodical and self-sufficient individual who has successfully delivered system migrations before not merely built data pipelines.Key Responsibilities Clean, deduplicate and validate large historical datasetsMap legacy data structures to new system modelsReconcile record counts and perform field-level validationIdentify data that should not be migrated (e.g. obsolete, non-billable)Support test migrations, dry runs, UAT cycles and final cutoverManage incremental loads and controlled re-runsDocument mapping decisions and migration logic clearlyCollaborate closely with Development and Engineering teams to resolve data issuesSupport post-migration fixes with minimal business disruption Candidate Profile Proven experience delivering data migration programmesStrong SQL skills and advanced data manipulation capabilityExperience reconciling high-volume transactional dataExposure to ITSM, Finance or Billing system migrations is highly desirableComfortable working independently in a fast-paced environmentExcellent documentation and validation discipline ..... full job details .....