Information Systems Security Engineer

We're hiring an Information Systems Security Engineer (ISSE) to support mission-critical work in a classified environment. In this role, you'll help build, secure, and maintain systems by applying cybersecurity engineering best practices across design, implementation, authorization, and ongoing compliance.

You'll be hands-on with the Risk Management Framework (RMF), Assessment & Authorization (A&A), ATO sustainment, control validation, continuous monitoring, and vulnerability/stig compliance efforts-partnering closely with security and technical teams.

WHAT YOU'LL DO

• Support the full RMF lifecycle for classified systems (from planning through continuous monitoring)
• Contribute to A&A packages and help maintain ATOs over time
• Implement, assess, and validate security controls and technical requirements
• Build and maintain RMF documentation and "body of evidence" artifacts
• Support system boundary definition and security architecture documentation
• Run and analyze compliance/vulnerability scans; validate results (including false positives)
• Support STIG implementation, configuration hardening, and remediation verification
• Help manage patch validation and ongoing security compliance activities
• Participate in Continuous Monitoring (ConMon) activities and reporting

• Active TS/SCI with Polygraph security clearance
• DoD 8570/8140 IASAE Level II compliant certification (required)
• Strong working knowledge of RMF
• Experience supporting A&A activities and ATO processes
• Experience implementing/validating security controls and supporting continuous monitoring
• Familiarity with NIST SP 800-37 and NIST SP 800-53 (Rev. 3 and/or Rev. 5)
• Experience with RMF/cybersecurity tools such as: LATTEART, XACTA, BISCOTTI, WATCHCAT, STE
• Experience using compliance and configuration scanning tools
• Strong documentation, analytical, and troubleshooting skills

NICE TO HAVE

• Experience working in classified cybersecurity environments
• Familiarity with enterprise Linux, networking, and/or cloud environments
• Experience partnering with ISSOs, ISSMs, SCAs, and System Owners
• Experience supporting large-scale enterprise or mission systems
• Exposure to vulnerability management automation and reporting workflows

Pulled from the full job description

• 401(k)
• Health insurance
• Vision insurance
• Dental insurance
• Life insurance

System One, and its subsidiaries including Joulé and Mountain Ltd., are leaders in delivering outsourced services and workforce solutions across North America. We help clients get work done more efficiently and economically, without compromising quality. System One not only serves as a valued partner for our clients, but we offer eligible employees health and welfare benefits coverage options including medical, dental, vision, spending accounts, life insurance, voluntary plans, as well as participation in a 401(k) plan.