Senior Systems Administrator

Senior Systems Administrator – InfrastructureWe are seeking an experienced Senior Systems Administrator – Infrastructure to support a large, mission-critical public-sector technology environment in the Tampa area. This individual will be responsible for the administration, reliability, security, and availability of enterprise infrastructure supporting 24/7 operations. The environment includes Windows and Linux systems, Active Directory, Microsoft 365, Azure/Entra ID, VMware, cloud infrastructure, enterprise storage, backup and disaster recovery technologies, and security platforms. The ideal candidate is a hands-on infrastructure professional who can independently troubleshoot complex issues, take ownership of systems and projects, and work effectively across both traditional on-premises and cloud environments.Key Responsibilities:Administer and support Microsoft Active Directory, including Group Policy, organizational units, permissions, auditing, backup, and recovery.Administer Microsoft Entra ID and Identity and Access Management (IAM) technologies.Maintain and support Microsoft 365 and enterprise email environments.Provide administration and operational support for Microsoft Azure cloud infrastructure.Configure and support AWS and other cloud environments as required.Administer VMware virtual environments, including VMware vSphere/ESXi.Support Windows Server 2019+ and enterprise Linux environments, including Red Hat.Administer enterprise storage technologies, including SAN, NFS, and Fibre Channel environments.Support enterprise backup, recovery, and disaster recovery technologies.Administer enterprise security technologies including SIEM, endpoint protection, anti-virus/anti-malware, and Mobile Device Management (MDM) platforms.Install, configure, troubleshoot, upgrade, patch, and maintain enterprise servers, applications, and supporting infrastructure.Monitor infrastructure availability, utilization, performance, and capacity using enterprise monitoring tools.Perform routine security audits, compliance reviews, and vulnerability scans.Create and maintain custom scripts to automate system administration and operational tasks.Create and manage Group Policy Objects (GPOs).Perform root-cause analysis for major incidents and recurring infrastructure problems.Build and deploy software packages using enterprise software distribution tools.Maintain accurate physical and virtual hardware/software inventories.Maintain detailed system configuration, technical process, and operational documentation.Participate in infrastructure, security, cloud, and systems integration projects.Evaluate new technologies, vendor products, and services.Manage and resolve infrastructure-related incidents and requests through an enterprise ticketing system.Collaborate with infrastructure, network, security, application, and other technology teams.Participate in a rotating on-call schedule as required.Support occasional after-hours maintenance, emergency response, or system recovery activities.Required Qualifications:Candidates should have a strong background administering enterprise infrastructure environments and meet one of the following experience levels: Bachelor's degree in a technical field and approximately 5+ years of relevant enterprise systems administration experience; Associate degree in a technical field and approximately 6+ years of relevant experience; or High school diploma/GED and approximately 7+ years of relevant enterprise infrastructure experience. Relevant experience should include several of the following areas: Windows Server administration Active Directory and Group Policy Microsoft Entra ID / Azure AD Microsoft 365 VMware virtualization Linux administration Cloud infrastructure Enterprise storage Backup and disaster recovery Systems security Infrastructure monitoring Systems integration Scripting and automation Basic enterprise networking and troubleshootingPreferred Qualifications:Strong preference will be given to candidates with experience in several of the following: 8+ years of enterprise systems administration experience VMware vSphere / ESXi administration VMware NSX VMware Workspace ONE Microsoft Azure administration Microsoft Entra ID and Exchange administration AWS administration Red Hat Enterprise Linux Enterprise SAN and SAN fabric administration Enterprise backup platforms Advanced PowerShell or other scripting experience Server hardware and virtual environment capacity planning Enterprise disaster recovery planning Security compliance and vulnerability management Supporting highly available or 24/7 technology environments Red Hat Certified Systems Administrator (RHCSA) or similar technical certifications are a plus.Skills & Competencies:Strong troubleshooting and root-cause analysis skills Ability to independently manage systems and technical assignments Strong understanding of enterprise infrastructure architecture Ability to quickly learn unfamiliar technologies Strong documentation and technical communication skills Ability to manage multiple priorities in a mission-critical environment Strong attention to security, availability, reliability, and data integrity Ability to collaborate effectively with technical teams, management, vendors, and business stakeholdersAdditional Requirements:This position supports a public-sector environment and will require successful completion of an extensive pre-employment background screening process. Candidates must be comfortable working onsite in Tampa during the initial onboarding period. The position is expected to transition to a hybrid schedule thereafter, with the specific timeframe and onsite/remote schedule to be determined. Occasional travel to other local facilities and participation in an on-call rotation may be required.