Top Senior System Administrator Jobs

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.

Lead administration, configuration, and optimization of the ServiceNow platform. Manage upgrades, integrations, performance monitoring, and architecture. Act as technical escalation, liaise with stakeholders and vendors, create operational documentation and KPIs, and participate in a 24x7x365 on-call rotation to ensure platform stability and scalability.

Lead and sustain HPC system operations for NOAA NWS, managing schedulers and system software, troubleshooting multi-node environments, improving performance and throughput, using Linux administration, PBS Pro/Slurm, scripting (Bash/Python/Perl), MPI, and participating in 24/7 on-call rotations with occasional travel for collaboration and training.

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

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.

Support and administer enterprise classified Red Hat Linux systems and HPE HPC clusters for the DARC program. Tasks include provisioning, integration, patching, user/account management, diagnostics, performance and reliability improvements, and collaboration with cybersecurity, software, hardware, and systems engineering teams. Participate in SkillBridge training pipeline for transitioning service members.

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.

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.

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.

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

Lead SAP BASIS administrator responsible for managing a 30+ system SAP landscape (ABAP and JAVA), providing technical guidance, performance tuning, upgrades, DR/backup, capacity planning, client copies, UNIX scripting, and mentoring junior admins while coordinating with functional, development, and infrastructure teams.

Design, implement, and maintain enterprise-scale Windows Server and Active Directory infrastructures, endpoint and patch management, and identity/access controls. Provide architecture for Group Policy, SCCM/JAMF/Intune, cross-platform endpoint management, automation scripting, and compliance with NIST/CMMC. Support end users, coordinate patching, and ensure reliable IT operations for site mission systems.