Sigma Defense

Software-driven CJADC2 and C5ISR systems

Network Security Engineer 3

Security Engineering & ArchitectureUpdated on Nov 11

Full-timeSan Diego, CA, USA$120k - $150k /yrIn-person

About the Job

Requirements

Five to ten years of experience.
Must be a U.S. citizen.
Must hold Security+ CE or CISSP certification.
Must hold at least one operating system or platform certification: Linux, Windows, VMware, or Cisco.
Must possess or be able to obtain an active Secret security clearance or higher.
Must have a bachelor's degree from an accredited college or university.

Responsibilities

Implement and enforce Department of Defense cybersecurity policies, including STIGs, RMF, and NIST SP 800-53, across CANES systems.
Design, develop, implement, and troubleshoot solutions for vulnerabilities within the CANES system.
Lead efforts to harden Windows and Linux systems, applications, network devices, and other hardware within the CANES environment.
Assist with IAVM compliance, log analysis, and audit readiness tasks.
Perform patch management, system scanning, and incident response coordination.
Maintain system documentation, cybersecurity artifacts, and baseline reports.
Support system validation during test events, site assessments, and production installations.
Design, develop, and automate configurations on supported platforms.
Administer and engineer RHEL 7 or later and Windows systems, including Windows Server versions 2019/2020 through 2025 or later.
Work with SIEM/SOAR platforms, including ArcSight, Splunk, and Sentinel.
Engineer ACAS solutions beyond basic user-level experience.
Engineer Trellix ESS solutions beyond basic administration.
Submit configuration updates via GitLab, GitHub, and Spork/Spork+.

Desired Qualifications

Experience with Sentinel and Splunk is preferred.

1784 - Network Security Engineer III

Sigma Defense · San Diego, United States · Full-time · Posted 2026-11-10

Salary: USD 120,000–150,000

Workplace: on_site

Department: IMS (IMSENG, IMSPRG, IMSNM, IMST&R)

Description

Sigma Defense is seeking a Network Security Engineer III to join our team in San Diego, CA. This position supports the enforcement of DoD cybersecurity policies (STIGs, RMF, NIST SP 800-53) across CANES environments while leveraging expertise in ACAS, Trellix ESS, NetIQ Sentinel, and Splunk. This role requires hands-on system hardening, vulnerability management, and configuration automation via GitLab, GitHub, and Spork/Spork+.

Equal Opportunity Employer/Veterans/Disabled: 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.

Requirements

5 - 10 years of experience.
Must be a U.S. citizen.

Computer Programs/Software:

ACAS
Trellix ESS
Spork/Spork+
NetIQ SIEM Sentinel

Mandatory Certifications:

Security+ CE or CISSP
At minimum one of the following operating system/platform certifications:
Linux
Windows
VMware
Cisco

Personnel Clearance Level:

Candidate must possess or have the ability to obtain an active Secret security clearance or higher.

Education Requirements:

Bachelor's degree from an accredited college or university.

Essential Job Duties (not all-inclusive):

Implement and enforce DoD cybersecurity policies (STIGs, RMF, NIST SP 800-53) across CANES systems.
Design, Develop, implement and troubleshoot solutions for vulnerabilities within the CANES system
Lead efforts to harden Windows/Linux systems, applications, network devices, and various hardware within the CANES environment.
Assist with IAVM compliance, log analysis, and audit readiness tasks.
Perform patch management, system scanning, and incident response coordination.
Maintain system documentation, cybersecurity artifacts, and baseline reports.
Support system validation during test events, site assessments, and production installations.
Design, develop, and automate configurations on the following platforms:
RHEL expertise/Admin (RHEL 7+ ideal)
Windows expertise/Admin (Win2019/2020 -> 2025+
SIEM/SOAR, (ArcSight/Splunk/Sentinel etc. Sentinel & Splunk experience Preferred!)
ACAS (engineering, not just user experience)
ESS (Trellix) Engineering (not admins)
Submit configuration updates via GitLab/GitHub, Spork/Spork+.

Salary Range: $120,000 - $150,000 annually.

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

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About the Company

Sigma Defense

Software-driven CJADC2 and C5ISR systems

Sigma Defense provides software-driven solutions that improve military communications and decision-making. It specializes in integrating advanced technologies, data analytics, and communication networks to create interoperable systems that share real-time information across all military services and agencies. Its CJADC2 focus means it bridges legacy systems with modern technology to speed access to data and enhance decision-making through sensor analysis and strong network security. The portfolio includes C5ISR, SATCOM, and DevSecOps, and features a Tactical Relay System (a U.S. Government Program of Record) that transports and distributes tactical ISR data. The company uses DevSecOps to enable rapid, secure deployment of capabilities to front-line users, with a team of veterans and technologists developing hardware and software solutions to improve decision quality, speed, and certainty in military operations.

Company size: 51-200
Company stage: Not listed
Total funding: Not listed
Headquarters: Warner Robins, GA
Founded: 2006

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