Design, deploy, upgrade, and administer Active Directory Domain Services, including domain controllers, forests, domains, trusts, and replication topologies (i.e. Manage and optimize Group Policy Objects (GPOs), OU structures, and security baselines; including object management through bulk operations and automation, Troubleshoot and resolve complex AD-related issues, including authentication failures, replication problems, DNS issues, and Kerberos/NTLM problems, Plan and execute Active Directory migrations, consolidations, and upgrades (of both underlying server infrastructure and overall forest/domain functional levels), Develop and maintain disaster recovery, backup, and restore procedures for AD environments (including AD Recycle Bin and authoritative restores), Monitor AD health and performance using tools such as Microsoft System Center, Azure Monitor, or third-party solutions). Deep expertise in designing, deploying, upgrading, and administering Microsoft Active Directory Domain Services (AD DS), including domain controllers, multi-domain/forest architectures, trusts, replication topologies, Group Policy Objects (GPOs), OU design, and security baselines.