Administers and engineers enterprise identity and messaging services across Active Directory, Entra ID, Exchange, Exchange Online, and hybrid Microsoft environments. Responsibilities include infrastructure design, security hardening, identity synchronization, authentication, network troubleshooting, compliance, automation, cloud modernization, documentation, and Tier III support within complex federal environments. The role requires extensive PowerShell automation, federal cybersecurity compliance, incident response support, and participation in on-call rotations.