Virtualization & Compute: Design, implement, administer, and optimize VMware environments, including ESXi hosts, vCenter Server, clusters, High Availability, Distributed Resource Scheduler, vMotion, virtual networking, templates, snapshots, and virtual machine lifecycle management. Windows Infrastructure: Install, configure, patch, harden, monitor, and troubleshoot Windows Server operating systems across production, disaster recovery, testing, and development environments. Identity & Core Services: Administer Active Directory Domain Services, including forests, domains, organizational units, users, groups, service accounts, delegation, replication, trusts, and domain controller health. DNS, DHCP & Group Policy: Configure, maintain, and troubleshoot DNS zones and records, DHCP scopes and reservations, IP address allocation, and Group Policy Objects, including security baselines and controlled policy deployment. Linux & Red Hat Platforms: Support Red Hat Virtualization and Linux operating systems, including installation, configuration, patching, services, permissions, file systems, performance monitoring, and incident resolution. Storage Management: Administer enterprise SAN, NAS, block, file, and object storage where applicable. Perform LUN and volume provisioning, zoning coordination, RAID configuration review, multipathing, capacity forecasting, performance analysis, replication, and storage lifecycle management. Backup & Recovery: Operate and maintain enterprise backup solutions; define and monitor backup policies, retention, replication, encryption, and recovery jobs; perform regular restore tests; and ensure alignment with approved RPO and RTO targets. Data Center Management: Coordinate rack-and-stack activities, cabling, labeling, asset placement, power and cooling requirements, environmental monitoring, access controls, capacity utilization, equipment movement, and coordination with facilities and service providers. Hardware Specifications: Review and validate server and storage hardware specifications, including CPU architecture and sizing, memory configuration, disks and SSDs, RAID controllers, HBAs, NICs, GPUs where applicable, power supplies, firmware, supportability, compatibility matrices, and vendor lifecycle status. Operations & Support: Monitor infrastructure health, availability, utilization, capacity, and performance; provide Level 3 technical support; lead root cause analysis; and implement permanent corrective and preventive actions. Lifecycle, Security & Compliance: Plan and execute upgrades, patching, firmware updates, vulnerability remediation, configuration hardening, certificate renewal, and end-of-life or end-of-support replacement activities. Documentation & Collaboration: Maintain architecture diagrams, build documents, standard operating procedures, recovery procedures, configuration records, asset inventories, and operational reports. Collaborate with network, cybersecurity, cloud, application, database, and vendor teams.