This senior engineering position manages AD objects, organizational units, Group Policy Objects (GPOs), trusts, replication, schema governance, delegated permissions, domain services, and recovery capabilities. Maintain AD sites, subnets, site links, and replication topology; troubleshoot replication failures, latency, and lingering objects; and maintain domain-controller health, SYSVOL, DFSR, time sync, AD-integrated DNS, and FSMO roles.