Senior Systems Administrator – Linux/Windows

. Support on-premises Linux (60%) and Windows (40%) infrastructure and applications .

Posted 4/29/2026full-timeArlington • Virginia • 🇺🇸 United StatesSenior💰 $110,800 - $185,100 per yearWebsite

Tools & technologies

AnsibleCloudCyber SecurityDNSDockerLinuxOracleVMware

Key responsibilities & impact

Support on-premises Linux (60%) and Windows (40%) infrastructure and applications
Support on-premises vSphere infrastructure across multiple datacenters
Provide Tier III support for production and development environments, managing ticket submission and tracking
Monitor resource availability to meet customer requirements, ensuring sufficient hardware, software, and throughput
Review and optimize system performance to ensure peak efficiency and reliability for mission-critical applications
Analyze system resource usage and apply corrective actions when necessary
Review system and application logs, ensuring completion of scheduled tasks and backups
Create and manage user accounts, groups, and permissions; maintain local repositories in a Linux-based environment
Support on-prem and remote Linux-based Oracle database appliances
Develop and maintain administrative bash scripts for system maintenance and automation
Proficient in DNS administration
Document and implement system administration solutions to meet business requirements
Provide project status updates, problem resolution, and system administration reports to management
Coordinate problem resolution with customers, team members, and vendors as needed
Assess and recommend improvements for system software and hardware to enhance efficiency and functionality
Collaborate with the Cybersecurity team to implement, monitor, and maintain cybersecurity compliance and vulnerability mitigations

What you’ll need

Active TOP SECRET clearance with SCI eligibility required; Program Access Request (PAR) submission required after hire
Bachelor’s degree in a STEM discipline (or additional years of relevant experience considered in lieu of degree)
8-10 years of IT Systems Administration that includes 3-5 years of Linux administration
DoD 8140 IAT Level II cert (e.g., Security+ CE or equivalent)
Experience designing and maintaining secure, scalable cloud/on-prem platforms (IL5–IL6+)
Knowledge of STIGs, RMF, and DoD cybersecurity standards
Knowledge of containerization (Docker/Podman), Ansible for automation, and OpenLDAP
Experience with virtualization (VMware)
Familiar with CLI and Bash scripting
U.S. Citizenship Required for the purposes of obtaining/holding a U.S. security clearance

Comp & perks

ATS Keywords

✓ Tailor your resume

Applicant Tracking System Keywords

Tip: use these terms in your resume and cover letter to boost ATS matches.

Hard Skills & Tools

Linux administrationWindows administrationvSphereOracle databaseBash scriptingDNS administrationCloud platformsVirtualizationContainerizationAnsible

Soft Skills

problem resolutioncommunicationcollaborationproject managementcustomer support

Certifications

TOP SECRET clearanceBachelor’s degree in STEMDoD 8140 IAT Level II certSecurity+ CE