1773 - System Administrator

📋 Job Overview

Sigma Defense is seeking a System Administrator to join our team at March Air Reserve Base. This position plays a key role in maintaining secure Department of War information systems by administering Windows and Red Hat Enterprise Linux (RHEL) environments, performing routine maintenance and patching, and ensuring reliable system operations. The Systems Administrator works closely with the engineering and cybersecurity teams to maintain secure, stable, and mission-ready infrastructure supporting Department of War operations.

🏢 About Sigma Defense

Sigma Defense Systems is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, or protected veteran status and will not be discriminated against on the basis of disability.

🎯 The Role

The Systems Administrator will be responsible for installing, configuring, maintaining, and troubleshooting Windows and RHEL systems, performing routine operating system patching, software updates, and system maintenance, maintaining physical and virtual server infrastructure, configuring and maintaining user accounts, storage, system services, and server resources, troubleshooting hardware, operating system, and application issues, supporting implementation of DISA STIGs and approved system configuration changes, maintaining system documentation, configuration baselines, and standard operating procedures, supporting system backups, recovery operations, and disaster recovery activities, supporting secure Cross Domain Solution (CDS) operations and associated system administration activities, coordinating with cybersecurity and network engineering personnel to implement approved system changes and maintain secure, reliable system operations, supporting testing, integration, and implementation of approved hardware and software changes, and monitoring system health, investigating operational issues, and resolving problems to maintain system availability and performance.

✅ Key Responsibilities

• Install, configure, maintain, and troubleshoot Windows and RHEL systems.
• Perform routine operating system 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, operating system, and application issues.
• Support implementation of DISA STIGs and approved system configuration changes.
• Maintain system documentation, configuration baselines, and standard operating procedures.
• Support system backups, recovery operations, and disaster recovery activities.
• Support secure Cross Domain Solution (CDS) operations and associated system administration activities.
• Coordinate with cybersecurity and network engineering personnel to implement approved system changes and maintain secure, reliable system operations.
• Support testing, integration, and implementation of approved hardware and software changes.
• Monitor system health, investigate operational issues, and resolve problems to maintain system availability and performance.

📌 Required 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 Security Technical Implementation Guides (STIGs).
• Experience maintaining secure Windows and/or RHEL system baselines.
• Experience administering RHEL in physical or virtualized environments.
• Experience with storage, backup, and disaster recovery solutions.
• Must be a U.S. citizen.

⭐ Desirable Experience

• Security+ is required.
• RHCSA is preferred.
• Network+ is preferred.
• Linux+ is preferred.
• Server+ is preferred.

🎁 Benefits

• Dental and Vision Insurance
• Medical Insurance to Include HSA, FSA, and DFSA Plans
• Life and AD&D coverage
• Employee Assistance Program (EAP)
• 401(k) Plan with Company Matching Contributions
• 160 Hours of Paid Time Off (PTO)
• 12 (Floating) Holidays
• Educational Assistance
• Highly Competitive Salary

🛂 Visa & Eligibility

• Candidate must possess or have the ability to obtain an active TS/SCI security clearance or higher.
• Clearance may be sponsored for the right candidate.