Information Systems Security Engineer (ISSE)

Information Systems Security Engineer (ISSE) Job ID: 2026-9716 Type: Full Time W/Benefits Ret Match Location: US-CO-Denver Secondary Location: US-CO-Colorado Springs Security Clearance: TS/SCI Overview Position is contingent upon contract award and funding. Entarian is seeking an experienced Information System Security Engineer (ISSE) to provide technical cybersecurity engineering expertise supporting the design, development, integration, implementation, and sustainment of secure information systems. The ISSE is responsible for integrating cybersecurity into system architectures throughout the system lifecycle, ensuring information systems comply with applicable government policies, cybersecurity standards, and Risk Management Framework (RMF) requirements. This role works closely with systems engineers, software developers, architects, ISSM/ISSO personnel, and government stakeholders to engineer secure, resilient solutions that support mission objectives while balancing security, performance, and operational requirements. The ideal candidate will have demonstrated experience supporting large-scale defense or space environments involving space systems, ground infrastructure, mission operations, communications networks, cloud environments, or enterprise information technology capabilities. Key Responsibilities Integrate cybersecurity requirements into system architecture, engineering designs, interface specifications, and technical documentation throughout the system lifecycle. Engineer, implement, and validate security controls in accordance with NIST RMF, NIST SP 800-53, CNSSI 1253, DoD guidance, and organizational cybersecurity policies. Perform technical security analyses including architecture reviews, vulnerability assessments, threat analysis, risk assessments, attack surface analysis, and mitigation planning. Participate in system architecture reviews, engineering design reviews, technical interchange meetings, and configuration control activities to ensure cybersecurity requirements are incorporated early in system development. Develop and maintain technical cybersecurity documentation including System Security Plan (SSP) content, control implementation statements, security architecture diagrams, data flow diagrams, network diagrams, interface documentation, and engineering analyses. Support development of Security Assessment Plans (SAPs), Security Assessment Reports (SARs), POA&Ms, continuous monitoring documentation, and other RMF artifacts supporting system authorization. Identify cybersecurity gaps, architectural weaknesses, and technical risks, and develop practical engineering solutions to improve the overall security posture. Collaborate with systems engineers, software developers, network engineers, cloud engineers, system administrators, and mission partners to establish and maintain secure configuration baselines. Evaluate proposed system changes, software releases, technology insertions, and architecture modifications for cybersecurity impacts and accreditation implications. Support vulnerability management activities including analysis of vulnerability scan results, prioritization of findings, remediation planning, and validation of corrective actions. Participate in integration, testing, verification, validation, and accreditation activities to ensure implemented security controls function as intended. Support continuous monitoring activities by assessing control effectiveness, monitoring security posture, and recommending improvements to maintain compliance. Ensure secure integration of Commercial Off-the-Shelf (COTS), Government Off-the-Shelf (GOTS), open-source, cloud-based, and custom-developed technologies. Provide technical cybersecurity guidance to engineering teams regarding secure system design, defense-in-depth strategies, Zero Trust principles, and cybersecurity best practices. Prepare technical reports, engineering recommendations, risk assessments, and executive briefings supporting senior leadership and government decision-makers. Salary range: $154,000.00 - $192,000.00 Minimum Qualifications Active Top Secret security clearance with SCI eligibility. Bachelor's degree in Cybersecurity, Information Technology, Computer Science, Engineering, or a related technical discipline. Equivalent experience may be considered. Minimum fifteen (15) years of experience performing information system security engineering for Department of Defense, Intelligence Community, federal, or space-related systems. Demonstrated experience implementing and engineering NIST RMF security controls in accordance with NIST SP 800-37, NIST SP 800-53, CNSSI 1253, and applicable DoD cybersecurity guidance. Strong understanding of secure systems engineering principles, security architecture, defense-in-depth, secure configuration management, and cybersecurity risk management. Experience supporting complex enterprise, cloud, communications, mission operations, or space systems throughout the system development lifecycle. Experience with operating systems, networking, virtualization, cloud technologies, identity and access management, encryption technologies, and modern cybersecurity solutions. Experience conducting vulnerability assessments using tools such as ACAS, Nessus, SCAP, or comparable vulnerability management platforms. Ability to produce high-quality engineering documentation, technical analyses, architecture recommendations, and RMF artifacts. Security certification meeting DoD 8140 (or legacy DoD 8570) requirements, such as Security+, GSEC, CISSP, CASP+, or IASAE certifications. Proficiency with Microsoft Office Suite, including Word, PowerPoint, Excel, Project, and Outlook. Ability to travel approximately 25% to support customer locations, mission partner engagements, cybersecurity assessments, and operational activities. Desired Qualifications Experience supporting Department of Defense, Intelligence Community, U.S. Space Force, or other classified government information systems. Experience designing and implementing Zero Trust Architecture principles within enterprise or mission systems. Experience supporting cloud security, hybrid cloud environments, containerized applications, Kubernetes, or DevSecOps pipelines. Familiarity with Infrastructure as Code (IaC), automation, scripting, or configuration management tools such as PowerShell, Python, Ansible, or Terraform. Experience performing security architecture reviews for large-scale, distributed, or systems-of-systems environments. Advanced cybersecurity certifications such as CISSP-ISSEP, CCSP, CASP+, GIAC GSEC, or comparable engineering-focused certifications. Experience supporting secure software development, software assurance, DevSecOps, or software factory environments. Familiarity with DoD Enterprise DevSecOps Reference Design, Platform One, or cloud-native security technologies. Excellent written and verbal communication skills with the ability to communicate complex cybersecurity concepts to technical teams, program leadership, and government stakeholders. Equal Opportunity Entarian is an Equal Opportunity and Affinitative Action Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, pregnancy, sexual orientation, gender identity, national origin, age, protected veteran status, or disability status. #J-18808-Ljbffr ERT, Inc.