Network Security Engineer III

📋 Job Overview

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+.

🏢 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

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+.

✅ Key Responsibilities

• 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+.

📌 Required Qualifications

• 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.

🎁 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

• Must be a U.S. citizen.
• Candidate must possess or have the ability to obtain an active Secret security clearance or higher.