Top Senior System Administrator Jobs

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).

Manage, install, configure, and maintain secure Linux servers and infrastructure (RHEL/Oracle Linux). Build custom images, automate deployments with scripting, integrate security tools (NESSUS, HBSS, Trellix, Splunk), perform vulnerability remediation and RMF/JSIG compliance, support ADDS, virtualization, backups/restores, and provide documentation and stakeholder communications for defense and simulation programs.

Provide system administration for Windows and Linux environments: monitor performance, apply patches, manage AD/DNS/DHCP, implement backup and security controls, support virtualization and VDI, and assist with system design, documentation, and incident response for mission-critical platforms.

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.

Senior Systems Administrator responsible for maintaining and securing enterprise Windows Server, virtualization (Hyper-V), storage (SAN), networking (firewalls, switches, wireless, VPN/WAN), Microsoft 365/Azure services, and automation via PowerShell. Serves as senior escalation, leads troubleshooting, participates in DR planning, mentors junior staff, and supports infrastructure projects and security controls.

Provide senior systems administration and PITCO coordination for Navy C4I modernization (CANES/TACNET). Ensure secure, compliant configurations, manage installations, patching, troubleshooting, documentation, schedules, SOPs, and technical risk mitigation to deliver operationally ready systems.

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.

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.

Provide 24/7/365 on-site Tier 1/2 mission support: monitor systems with SolarWinds/Splunk/Wireshark, triage hardware/software/network faults, support Layer 1-3 networking, respond to mission-critical incidents, perform checks and testing, maintain SOPs and configuration management using BMC Remedy.

Senior Systems Administrator responsible for designing and implementing infrastructure changes, managing VMware/Nutanix virtual environments, administering Windows Server and Linux, creating STIG-compliant images, deploying software via SCCM/PDQ, scripting automation (PowerShell/Bash), mentoring junior staff, and administering Active Directory, GPO, DNS, and DHCP.

Provide on-site systems administration for classified DoD environments (SIPR), managing Windows/Linux servers, virtualization, storage, backups, encryption, and user-requested software. Troubleshoot hardware/software issues, collaborate with cybersecurity, obtain DoD 8140/8570 certification within six months, and support 24x7 operations with occasional travel (up to 10%).

Provide systems administration for classified environments across Windows and Red Hat Enterprise Linux. Manage AD, DNS, DHCP, VMware virtual infrastructure, storage/backup (RAID/NAS/SAN), and collaborate with cybersecurity to meet DoD security requirements. Maintain 24x7 systems, troubleshoot complex OS/hardware integration issues, produce documentation/training, obtain required DoD certifications, and support occasional domestic travel. Position is full-time onsite in Tucson and requires security clearance.

The Senior System Administrator will manage IT systems' implementation, troubleshooting, and maintenance while overseeing daily operations, providing support, and optimizing system performance.

Provide onsite systems administration for SIPR and other information systems in a heterogeneous Windows/Linux environment. Manage virtualization, server hardware, RAID, encryption, AD/DNS/DHCP, backups/restores, software installs, and collaborate with cybersecurity. Maintain 24x7 systems, obtain DoDD 8140/8570 certification (e.g., CompTIA Security+ CE) within six months, and travel domestically up to 10% annually.

Manage, maintain, and optimize enterprise Linux (RHEL/CentOS) infrastructure and VMware virtualization supporting high-availability mission systems. Administer middleware (JBoss), perform patching/upgrades, troubleshoot OS/middleware/virtualization issues, implement automation, support security/compliance, develop operational documentation, and provide 24x7/after-hours support in a secure production environment.

The role involves managing Linux servers, supporting Red Hat environments, ensuring system security, and troubleshooting issues. A Top Secret/SCI Clearance is required.

Provide systems administration for Windows and Red Hat Enterprise Linux in a classified environment. Troubleshoot OS and hardware integration, manage AD/DNS/DHCP and server replication, support security/compliance and hardening, collaborate with cybersecurity teams, document and train, meet DoDD 8140/8570 certification within six months, and support 24x7 operations with occasional after-hours work.

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

The Senior Systems Administrator manages system administration tasks for production and non-production environments, oversees maintenance, troubleshooting, and documentation, while providing guidance to team members.

The Senior Systems Administrator will support IT systems management, including troubleshooting, maintenance, and system security compliance, while configuring Linux systems and virtualization infrastructure.

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.

Administer and maintain Linux (RHEL/CentOS/Ubuntu) and Windows Server environments (AD, Group Policy); automate tasks with Python/Bash/PowerShell; monitor and troubleshoot systems; manage virtualization (VMware/Hyper-V), backups, security, user accounts, and documentation while collaborating with infrastructure and application teams.

Provide systems administration and cybersecurity support for GPS IIF satellite systems: integrate and configure multiplatform hardware/software, manage AD/LDAP domains, perform patching across Solaris/RHEL/Windows, run vulnerability and compliance scans (Nessus, SCC), apply DISA STIG hardening, maintain documentation, support deployments, automation, and on-call mission operations to ensure system reliability and compliance with NIST and DoD requirements.