Top Senior System Administrator Jobs

The Senior System Administrator will oversee the administration and security of Linux systems, manage updates, and ensure operational stability in cloud environments.

Senior System Administrator responsible for engineering, administering, and supporting enterprise endpoint environments. Duties include deploying and maintaining Windows/macOS endpoints, virtual desktop and cloud-based platforms, implementing security controls and compliance, troubleshooting complex issues, automating tasks with PowerShell, participating in endpoint modernization (Intune, Autopilot, Windows 365, AVD), and working with Security, Infrastructure, and Service Desk teams to ensure stable, secure endpoint operations.

Lead administration and support of corporate Microsoft infrastructure, VDI/RDS access platforms, virtualization, storage, backups, and cloud services. Perform AD domain/forest migrations, replace legacy VDI and load‑balancing stacks, maintain documentation, resolve incidents to SLA, participate in projects and on‑call rotation, and collaborate with NOC, InfoSec, DevOps, and L2 teams.

The Senior Systems Administrator supports PMIS by managing system performance, user access, troubleshooting, training, and system integrations. They ensure alignment with project management processes and work closely with stakeholders for effective use of PMIS.

Senior Systems Administrator responsible for IT systems support, troubleshooting, virtualization management, and scripting for system configurations and dataflows.

Responsible for day-to-day systems administration, support of Linux environments, troubleshooting, managing maintenance tasks, and providing technical guidance to the team.

Provide system administration and troubleshooting for complex, geographically distributed and air-gapped environments. Maintain servers, AD, virtualization, patching, vulnerability management, backups, security controls, documentation, and user/support communication. Support system engineering requests, perform cert renewals, and optimize application performance.

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

Manages and supports large-scale HPC clusters, servers, storage, networking, software stacks, scheduling systems, and scientific applications. Responsibilities include Linux and Windows administration, monitoring, troubleshooting, automation, patching, security maintenance, backups and restores, software deployment, vendor coordination, documentation, and user support. The role also contributes to HPC hardware and software procurement and requires three days onsite weekly.

Administers and maintains enterprise collaboration platforms, primarily Microsoft 365, Teams, Zoom, and related applications. Responsibilities include configuration, access management, monitoring, incident escalation, troubleshooting, maintenance, change validation, workflow and automation support, documentation, licensing, compliance controls, vendor coordination, and operational improvements. Provides technical guidance and on-call support while partnering with engineering, security, compliance, quality, business, and support teams.

Administer and integrate Linux, UNIX, and Windows systems, networks, storage, and virtual environments. Configure infrastructure, troubleshoot complex hardware and software issues, provide Tier 1 and Tier 2 support, optimize capacity and performance, and contribute to systems and mission-architecture design within SOA environments. Communicate technical issues and resolutions to management and internal customers while maintaining reliable mission infrastructure.

This role involves providing senior-level technical leadership for Windows-based server environments, including architecture, administration, troubleshooting, and managing infrastructure projects.

Responsible for supporting server and desktop operating systems, virtualization, storage management, and hardware troubleshooting. Leadership and communication skills are essential.

Maintain, update, and secure servers, databases, and installed server applications. Provide expert desktop support for Windows, macOS, and Linux to faculty and staff. Manage file shares, perform server backups, maintain IT asset inventory, configure and connect devices, monitor network and server performance, and respond to help desk issues.

Responsible for the administration of MS Windows Servers and VMware environments, troubleshooting issues, supporting users, and managing product lifecycles.

The role involves administration and maintenance of Windows-based servers, applying security updates, monitoring system performance, and supporting end-user IT automation, applicable for both Senior and Junior levels.

As a Senior AWS DevOp and System Administrator, you'll design, deploy, and maintain reliable infrastructure on AWS, ensuring optimal performance and security while collaborating in an agile team.

Manage, maintain, and upgrade production Linux (CentOS/RedHat) servers and VMware infrastructure. Monitor systems with Nagios, develop automation scripts, implement security hardening, handle backups and disaster recovery, troubleshoot hardware/software and network issues, and support application deployments and system rollouts.

Responsible for designing, implementing, and supporting the Operational Technology infrastructure, ensuring system stability, security, and overall performance management in coordination with application support teams.

Senior Linux System Administrator to maintain on-premises and AWS Linux servers, support 24x7 on-call operations, perform security patching/STIG updates, manage RHEL subscriptions, automate administration tasks, assist cloud migrations, support A&A audits and ensure system backups, performance tuning, and certificate management while coordinating maintenance with stakeholders.

Manage and secure enclave development networks: administer Windows and Linux servers, VMware virtualization, Active Directory/GPO, storage (NetApp), networking, backups/recovery, troubleshooting, system hardening, compliance scanning (Nessus/ACAS), account/access management, and document operational procedures to meet RMF/security requirements.

Provide on-site systems administration and real-time support for ground systems supporting flight operations. Install, configure, troubleshoot, and maintain communications and computer systems, manage accounts and equipment, perform field integration and repairs on the flightline, support STIG compliance and security updates, and coordinate with engineers and MOBs for tests, maintenance, and data movement.

This role involves supporting Linux-based systems, managing VMware VMs, ensuring security compliance, and providing 24x7 operational support.

Lead design, deployment, maintenance, and troubleshooting of complex LAN/WAN and server infrastructures. Provide onsite customer support, manage Windows Server and Active Directory, virtualization (VMware), networking (switching, routing, VLANs, VPNs, wireless), email/DNS troubleshooting, backups, monitoring, and documentation. Mentor junior staff and design infrastructure projects aligned with best practices.

Lead administration, configuration, security, and change governance for business systems (e.g., NetSuite, DAP). Act as senior escalation for complex issues, manage access controls and audits, coordinate integrations and data management, mentor administrators, and ensure changes and documentation follow best practices.