Secure Systems Administrator – Windows & RHEL, CDS & STIGs

Sigma-Defense; March Air Reserve Base (CA); On-site; USD 115,000 - 135,000; Full time

Benefits offered by this job

Dental & Vision Insurance

Medical with HSA/FSA/DFSA

Life and AD&D

EAP

401(k) with company match

PTO 160 hours

12 floating holidays

Educational Assistance

Highly competitive salary

Job summary

Sigma Defense seeks a System Administrator to maintain Windows and RHEL environments at March Air Reserve Base. You will patch, configure, and support secure, mission-ready infrastructure in collaboration with cybersecurity and network teams.

The role requires 3–7 years of experience, DoD-related background, and active or sponsorable TS/SCI clearance. Equal opportunity employer with comprehensive benefits is offered.

Qualifications

• 3-7 years of relevant experience.
• Experience administering Windows Server and/or RHEL systems.
• Experience installing, configuring, maintaining, and troubleshooting server operating systems.
• Experience with virtualization technologies such as VMware ESXi.
• Experience performing operating system patching, maintenance, and lifecycle support.
• Basic understanding of networking concepts and enterprise infrastructure.
• Experience supporting secure or air-gapped Department of War environments.
• Experience with Cross Domain Solution (CDS) technologies.
• Experience with Full Motion Video (FMV) systems, platforms, or supporting infrastructure.
• Experience implementing or maintaining DISA STIGs.

Responsibilities

• Install, configure, maintain, and troubleshoot Windows and RHEL systems.
• Perform routine OS patching, software updates, and system maintenance.
• Maintain physical and virtual server infrastructure.
• Configure and maintain user accounts, storage, system services, and server resources.
• Troubleshoot hardware, OS, and application issues.
• Support implementation of DISA STIGs and approved system configuration changes.
• Maintain system documentation, baselines, and SOPs.
• Support system backups, recovery operations, and disaster recovery activities.
• Support CDS operations and related administration.
• Coordinate with cybersecurity and network engineering to implement approved changes.

Skills

Windows Admin

RHEL Admin

VMware ESXi

Patching & maintenance

Networking basics

Cross Domain Solution

FMV systems

STIGs implementation

System baselines

Scripting (Bash/PowerShell/Ansible)

Storage & DR

US citizen

Security clearance TS/SCI

Education

Bachelor's degree in IT or related field

Tools

Bash

PowerShell

Ansible

Job description

Sigma Defense seeks a System Administrator to maintain Windows and RHEL environments at March Air Reserve Base. You will patch, configure, and support secure, mission-ready infrastructure in collaboration with cybersecurity and network teams.

The role requires 3–7 years of experience, DoD-related background, and active or sponsorable TS/SCI clearance. Equal opportunity employer with comprehensive benefits is offered.