Top Senior System Administrator Jobs

Deploys, maintains, and secures enterprise IT infrastructure across Microsoft 365, Azure, Windows Server, VMware, storage, networking, communications, and security platforms. Provides second-level help desk support, leads technology initiatives, develops policies and procedures, tests disaster recovery and business continuity plans, remediates vulnerabilities, supports compliance, and manages vendor relationships. The role is primarily on-site with occasional nights and weekends for upgrades.

Provides system administration for a large, geographically distributed network with air-gapped environments. Responsibilities include installing applications, administering Linux and Windows systems, managing Active Directory, patching, hardening, vulnerability remediation, certificate renewals, backups, deployments, troubleshooting, virtualization, documentation, and system performance optimization. The role supports users and technical staff, resolves operational issues, and communicates outage and upgrade information. Travel includes local travel and occasional CONUS and OCONUS trips.

Administer and maintain UNIX, Linux, Windows, and virtual environments across client/server, storage, network, and mobile infrastructure. Troubleshoot complex system issues, provide Tier 1 and Tier 2 escalation support, configure network components, install operating-system software, optimize performance, perform capacity planning, and support system security and compliance. Communicate technical issues, system status, and resolution progress to agency management and internal customers.

Provide 24/7 Windows desktop and AV support across NIPRNet/SIPRNet/JWICS/SAP-SAR environments. Manage and maintain virtual machines and consoles (Teradici, WMS, 10Zig), troubleshoot hardware/software, administer print services, enforce DISA STIG compliance, develop technical documentation, perform lifecycle management and recovery testing, and deliver professional customer support at Offutt AFB under Top Secret/TS-SCI requirements.

Provides system administration for complex, geographically distributed and air-gapped environments. Responsibilities include installing and maintaining applications, configuring servers and desktops, managing Active Directory, patching, vulnerability assessments, certificate renewals, virtualization, backups, troubleshooting, security management, performance optimization, and technical documentation. The role supports end users and technical teams, resolves operational issues, coordinates outages and upgrades, and maintains server, storage, and network infrastructure.

The Senior System Administrator will evaluate system specifications, install and configure enterprise systems, and provide operational support, ensuring systems security and functionality while managing network performance and hardware requirements.

Responsible for the design, deployment, and maintenance of Linux/UNIX server systems and software, with virtualization and project support responsibilities.

Manage mission-critical cloud and on-premises infrastructure in a defense environment. Provision and monitor cloud services, administer Windows and Linux systems, maintain Docker and Kubernetes environments, secure networks, perform patching and hardening, implement compliance controls, support identity management, troubleshoot infrastructure issues, and maintain disaster recovery and backup strategies. Collaborate with security, compliance, and engineering teams to ensure operational readiness.

Provide combat system simulation support, implement network solutions, and maintain accreditation for Government wide area network usage.

Provide advanced systems administration for hybrid Windows and Linux enterprise environments (on-prem and AWS). Perform IAVA patching, vulnerability remediation, OS maintenance, software lifecycle support, automation (PowerShell, Terraform, Ansible), IaC, cloud administration (EC2, Lambda, CloudFormation), GPO management, troubleshooting, documentation, and cross-team collaboration to ensure security and availability of mission-critical systems.

Administers and maintains Windows and VMware infrastructure supporting a DoD intelligence-sharing program. Responsibilities include 24/7 incident response, VMware virtualization, Active Directory, Exchange, SharePoint, SQL Server, SCCM, Group Policy, system updates, security compliance, scripting, documentation, monitoring, troubleshooting, and performance tuning. The role requires Secret clearance, U.S. citizenship, shift work, and onsite work at MacDill AFB.

Lead and manage classified IT infrastructure operations: administer Windows and RHEL servers, VMware virtualization, storage, networking, and cybersecurity posture (DISA STIGs, Nessus). Maintain classified development/integration environments, perform after-hours maintenance, and achieve required certifications (e.g., McAfee ePO).

Administer Windows and Linux servers, virtualization (VMware/Hyper-V), enterprise storage, backup/recovery, and simulation software for Navy LVC training. Maintain RMF/STIG compliance, perform vulnerability remediation, support distributed training events, and provide operational support during major fleet exercises.

The role involves managing HPC systems, administering Linux servers, utilizing container technologies, and supporting storage systems. The candidate must collaborate with teams and address infrastructure needs while ensuring system optimization.

Provide onsite systems administration for Windows and Red Hat Enterprise Linux environments, manage DNS/DHCP/AD and server replication, troubleshoot OS and hardware integration issues, maintain virtualization and storage solutions, and meet DoD 8140/8570 certification requirements. Must hold active transferable Secret clearance.

Administer and troubleshoot heterogeneous Windows and Red Hat Enterprise Linux environments, manage DNS/DHCP/AD and server replication, perform scripting, system hardening, audit log collection, and support 24x7 operations. Collaborate with cybersecurity on compliance and vulnerability remediation, provide documentation and training, and support virtualization, imaging and deployment tasks. Active transferable Secret clearance and on-site work in Marlborough, MA required.

Support an IC-wide mission environment as a senior Linux Systems Administrator/Engineer. Require 10+ years Linux (CentOS/RHEL) experience, JBoss/Wildfly administration, VMware VM creation/operation, and Security+ certification. Desired skills include Red Hat Ansible, storage, networking, security compliance, authentication, shell/Python scripting, physical server administration, Oracle DB/DBA familiarity, JSON, and possession of/eligibility for high-level clearances.

Support an Intelligence Community mission environment as a senior Linux system administrator/engineer. Administer CentOS/RHEL systems, install/configure/maintain JBoss/Wildfly, manage VMware VMs, ensure security/compliance, perform scripting (Shell/Python), support storage, networking, authentication, physical servers, and occasional Oracle/DBA tasks. Must meet clearance and shift availability requirements.

Provide onsite Windows and Red Hat Enterprise Linux systems administration for classified DoD programs. Responsibilities include provisioning, configuration, troubleshooting, virtualization (VMware), storage and backup management, AD/DNS/DHCP administration, scripting/automation (PowerShell/Bash), security compliance, documentation, and 24x7 operational support. Collaborate with cybersecurity, network engineering, and program stakeholders; obtain DoD 8140/8570 certification (Security+ or equivalent) within six months.

Manage and maintain classified Linux and Windows server infrastructure onsite, including provisioning, backup/recovery, virtualization (VMware), storage (NAS/SAN), authentication, and security compliance. Collaborate with cybersecurity, network, and engineering teams, perform troubleshooting, document processes, and support 24x7 operations. Obtain required DoD/8570 certification within six months.

Senior System Administrator will maintain and tune Windows servers and VMware virtualization, oversee patching, deployments, and system security, support storage and disaster recovery, automate tasks with Kaseya and PowerShell, produce monitoring reports, update documentation, and lead infrastructure improvement projects.

The Senior System Administrator manages and maintains computerized systems in a cGMP environment, ensuring compliance and supporting users while coordinating with IT and QA.

Provide support for the design, configuration, and deployment of Windows Server environments, including virtualization and disaster recovery solutions.

The Senior System Administrator will design, configure, and support Windows Server environments, manage virtualization, and implement disaster recovery strategies.

Ensure immediate response to outages, support mainframe systems, analyze and resolve systems problems, and monitor software and hardware performance.