Principal Cyber Systems Engineer

Mid-Level / Senior Level | Mid-$90,000 - $112,000 Senior- $112,000 - $125,000 | Colorado Springs, CO | Onsite | Travel Up to 25% (CONUS & OCONUS) | Active Secret Clearance Required

Protect mission-critical defense systems by supporting cybersecurity engineering, Risk Management Framework (RMF) compliance, and continuous monitoring activities across classified environments. Join a collaborative engineering team responsible for securing next-generation defense systems through vulnerability assessments, security compliance, system hardening, and Assessment & Authorization (A&A) activities that enable mission success.

• Perform cybersecurity assessments of classified systems and networks to identify configuration drift, security vulnerabilities, and compliance deficiencies.
• Conduct compliance audits using tools such as STIG Viewer, Evaluate-STIG, STIG Manager, SCAP, SCC, and related assessment utilities.
• Develop, update, and maintain cybersecurity documentation including Security Assessment Plans (SAPs), Security Assessment Reports (SARs), Risk Assessment Reports (RARs), Plan of Actions & Milestones (POA&M), and RMF body-of-evidence artifacts.
• Support the full Risk Management Framework (RMF) lifecycle by preparing Assessment & Authorization (A&A) documentation and maintaining system accreditation packages within eMASS.
• Coordinate with government customers, System Program Office (SPO) personnel, Information System Security Managers (ISSMs), and engineering teams to resolve cybersecurity findings and maintain authorization status.
• Perform vulnerability assessments using ACAS, Nessus, Tenable.sc, and related security assessment tools to identify and remediate cybersecurity risks.
• Validate security controls and verify compliance with DoD cybersecurity requirements, including NIST, DoDI, AFI, and NISPOM guidance.
• Apply Security Technical Implementation Guides (STIGs) to harden Linux-based systems and verify secure system configurations.
• Analyze cybersecurity findings, recommend risk mitigation strategies, and support implementation of corrective actions across engineering teams.
• Collaborate with software developers, systems engineers, and infrastructure teams to integrate cybersecurity requirements throughout the system development lifecycle.
• Support continuous monitoring activities through recurring security assessments, audits, inspections, and compliance reviews.
• Research emerging cybersecurity technologies, evaluate new security tools, and recommend enhancements that improve overall system security posture.
• Support domestic and international travel (up to 25%) to assist with cybersecurity assessments, program reviews, and customer mission support.

• Bachelor's degree in a STEM (Science, Technology, Engineering, or Mathematics) discipline and 2 years of related professional experience; OR
• Master's degree with 0 years of related professional experience.

• Bachelor's degree in a STEM discipline and 5 years of related professional experience; OR
• Master's degree and 3 years of related professional experience; OR
• PhD and 1 year of related professional experience.

Both Levels Require:

• Active in-scope DoD Secret security clearance required at time of application.
• Current DoD 8570 IAT Level II certification (Security+ CE, SSCP, GSEC, CCNA Security, or equivalent).
• Experience applying DoD cybersecurity policies and standards including DoDI 8500.01, NIST SP 800-53, and NIST SP 800-115.
• Working knowledge of the Risk Management Framework (RMF) lifecycle, including security requirements development, security control assessments, vulnerability analysis, and Assessment & Authorization activities.
• Experience developing cybersecurity documentation and RMF artifacts supporting system accreditation.
• Experience performing vulnerability and compliance assessments using ACAS, Nessus, Tenable.sc, or equivalent scanning tools.
• Experience administering Linux systems in secure environments.
• Experience implementing and validating Security Technical Implementation Guides (STIGs).
• Strong technical writing, documentation, and analytical skills.
• Proficiency with Microsoft Office Suite.
• Ability to work onsite under a 9/80 schedule.
• Ability to travel up to 25% (CONUS and OCONUS).

• Active DoD Top Secret security clearance.
• Penetration testing certifications such as OSCP, OSCE, GPEN, GWAPT, or GXPN.
• Experience implementing or administering Security Information and Event Management (SIEM) and centralized log aggregation platforms.
• Experience conducting cybersecurity assessments of Red Hat Enterprise Linux (RHEL) environments.
• Strong understanding of networking concepts including:
  • TCP/IP networking
  • Subnetting
  • Firewalls
  • Network Address Translation (NAT)
  • Access Control Lists (ACLs)
  • VLANs
• Advanced experience using ACAS, Nessus, and Tenable.sc for enterprise vulnerability management.
• Experience implementing automated STIG compliance using Evaluate-STIG, STIG Manager, SCC, Xylok, Ansible, Python, or similar automation tools.
• Experience supporting Agile development methodologies including Scrum, Kanban, or SAFe.
• Experience using Jira, Confluence, or other Atlassian collaboration tools.
• Experience supporting VMware virtualization and containerized environments.
• Experience managing RMF packages within eMASS and supporting Authority to Operate (ATO) activities.
• Experience with the Elastic Stack (ELK) for security monitoring and analytics.
• Experience supporting Cross Domain Solutions (CDS), including coordination with CDSE and NCDSMO.
• Current DoD 8570 IAT Level III certification (CISSP or equivalent).

Caribou Thunder is a HUBZone-certified small business providing advanced technical and engineering services to the U.S. Department of War and its mission partners.

35+ states and 20+ countries.

We've delivered trusted solutions for over two decades-strengthening national readiness across missions on land, undersea, in the air, and throughout LEO, MEO, GEO, and deep space.

• Employee Advocacy
• Mission Proven
• Global Reach
• Skilled Teams
• Modern Tools
• Empowering Culture

Our engineers and innovators ensure capability from sea floor to space frontier-delivering on time, maintaining compliance, and performing with precision in high-consequence environments.

We specialize in Engineering Services, Cybersecurity, Software Development, Modeling & Simulation, Digital Engineering, Artificial Intelligence, and Secure Mission Systems-disciplines powering the nation's most complex technical missions.


Our people are the heart of Caribou Thunder. We invest in their growth, flexibility, and well-being-knowing their success drives ours.

Benefits include:

• Premium Health, Dental & Vision Insurance
• 401(k) with 6% Company Match
• Flexible PTO & Work Schedule
• Education & Certification Reimbursement
• Support for Military Leave
• Work-Life Balance & Traditional Family Values

Your future, your flexibility, your well-being-we invest in you.

Apply and let's connect.