System Administrator

Avint LLC is seeking a dedicated and technically skilled Mid-Level System Administrator for an on-site position in San Diego, CA. In this critical role, you will support and maintain enterprise IT infrastructure in a mission-driven environment, ensuring system reliability, security, and performance. You’ll be responsible for administering and monitoring servers, applying system patches and updates, managing user accounts, and supporting virtualization platforms. Experience with tools such as Active Directory, Windows Server, Linux, VMware or Nutanix, and scripting for automation (PowerShell, Bash, etc.) is essential. Familiarity with security tools and practices, including STIGs, vulnerability remediation, and participation in system accreditation processes, is highly desirable. This position involves working closely with IT, cybersecurity, and operations teams to support day-to-day system functionality, troubleshoot issues, and contribute to system hardening and compliance initiatives.

Location: 100% on-site in San Diego, CA.

Responsibilities:

• Administer and maintain Nutanix Hyperconverged virtual environments supporting FRCS Monitoring servers and associated applications.
• Deploy and manage Cyber Monitoring Services OT Monitoring Platform components—including Central Store, Site Store, and Sensors—in both test and operational environments.
• Configure and support Microsoft SQL Server and Windows Server environments, ensuring database and system stability in line with operational requirements.
• Utilize Marine Corps Certification and Accreditation Support Tool (MCCAST V2) to support system accreditation and compliance initiatives.
• Support and maintain network infrastructure in a Department of Defense (DoD) environment, ensuring secure and reliable connectivity.
• Understand system interface requirements with critical infrastructure domains such as high voltage, water/wastewater, and mechanical systems.
• Administer and secure Unix and Windows systems, applying knowledge of TCP/IP protocols, access controls, and security profiles.
• Manage and maintain Host-Based Security System (HBSS) to monitor and protect DoD systems from unauthorized activity.
• Support and troubleshoot Automated Metering systems used for energy monitoring and control.
• Apply knowledge of USMC DEVSECOPS policies to support cybersecurity compliance and operational resilience of ICS/OT systems.
• Administer, update, and troubleshoot ICS platforms including Metasys, Niagara AX, Alerton, Honeywell, Trend, KMC, American Automatrix, Loytec, Rockwell, and OSI.
• Support communication protocols and integration for building and utility systems using BACnet/MSTP, BACnet/IP, N2, LON, SCADA (High Voltage, Water/Wastewater).
• Perform routine software and security updates, patches, and version upgrades on OT/ICS systems such as Metasys, Niagara, Itron, Honeywell, Rockwell, and OSI.
• Execute and support the USMC Assessment & Authorization (A&A) process, including use of MCCAST 2.0, RMF, DFIA, and CNSSI 1253 standards.
• Track and manage Plans of Action and Milestones (POAMs) for system vulnerabilities and compliance findings.
• Apply DISA Security Technical Implementation Guides (STIGs) to harden and secure systems in accordance with DoD standards.
• Interpret and implement information security policies and controls in compliance with NIST 800-53 and DoDI 8510.01.
• Conduct system vulnerability and risk analyses to identify and mitigate threats.
• Operate and analyze data from the Dragos platform to support OT cybersecurity monitoring and threat detection.

Requirements

Experience:
Minimum 5 years of relevant IT/system administration experience supporting virtualized environments, networks, and OT systems.

Education:
Bachelor’s degree in Information Technology, Computer Science, Cybersecurity, or a related field.

Security Clearance:
Active Secret clearance required.

Certifications:
One or more of the following certifications (or equivalent) are highly desired:

• Cyber Monitoring Services Platform Certified User Certification
• ITIL v4 Foundations
• ICS-VLP Certificate (Courses 210W-01 through 210W-10)
• Risk Management Framework (RMF) Training – USMC specific
• Cisco Certified Entry Networking Technician (CCENT) or Cisco Certified Network Associate (CCNA)
• CompTIA Security+ (Sec+)
• Certified Information Systems Security Professional (CISSP)
• Microsoft Certifications (Server, Azure, or related)

Benefits

Joining Avint is a win-win proposition! You will feel the personal touch of a small business and receive BIG business benefits. From competitive salaries, full health, and generous PTO and Federal Holidays. Additionally, we encourage every Avint employee to further their professional development. To assist you in achieving your goals, we offer reimbursement for courses, exams, and tuition. Interested in a class, conference, program, or degree? Avint will invest in YOU and your professional development!

Avint is committed to hiring and retaining a diverse workforce. We are proud to be an Equal Opportunity and Affirmative Action Employer, making decisions without regard to race, color, religion, creed, sex, sexual orientation, gender identity, marital status, national origin, age, veteran status, disability, or any other protected class.

The salary range for this position is: $XXX - $XXX