Information Systems Security Engineer (ISSE) with Security Clearance

Entarian is seeking an experienced Information System Security Engineer (ISSE) to support the Naval Information Warfare Center Atlantic (NIWC Atlantic) Expeditionary Enterprise Systems and Services (E2S2) Division. NIWC Atlantic provides design, acquisition, and sustainment services for Marine Corps Systems Command (MCSC) Information Technology (IT) systems. The ISSE will integrate cybersecurity into system architectures throughout the system lifecycle, ensuring full compliance with government policies, cybersecurity standards, and Risk Management Framework (RMF) requirements.

This position partners closely with systems engineers, software developers, architects, ISSM/ISSO personnel, and government stakeholders to engineer secure, resilient solutions that support mission objectives. The ideal candidate will have experience supporting large-scale defense, intelligence, or space system environments involving space systems, ground infrastructure, mission operations, networks, cloud environments, or enterprise IT capabilities. Job Responsibilities include:

• Integrate cybersecurity requirements into system architecture, engineering designs, interface specifications, and technical documentation throughout the lifecycle.
• Engineer, implement, and validate security controls in accordance with NIST RMF, NIST SP 800-53, CNSSI 1253, and DoD cybersecurity guidance.
• Conduct architecture reviews, vulnerability assessments, threat analysis, risk assessments, attack surface analysis, and mitigation planning.
• Participate in architecture reviews, design reviews, technical interchange meetings, and configuration control boards to ensure cybersecurity is built in from the start.
• Develop and maintain technical cybersecurity documentation such as SSPs, control implementation statements, security and network diagrams, interface documents, and engineering analyses.
• Support RMF activities including SAPs, SARs, POA&Ms, continuous monitoring documentation, and other authorization artifacts.
• Identify cybersecurity gaps and architectural risks; recommend practical engineering solutions to strengthen security posture.
• Collaborate with engineering teams to establish and maintain secure configuration baselines.
• Evaluate system changes, technology insertions, and architecture modifications for cybersecurity impacts and accreditation implications.
• Support vulnerability management by analyzing scan results, prioritizing findings, planning remediation, and validating corrective actions.
• Participate in integration, testing, verification, validation, and accreditation activities to ensure security controls perform as intended.
• Support continuous monitoring by assessing control effectiveness and recommending improvements.
• Ensure secure integration of COTS, GOTS, open-source, cloud-based, and custom-developed technologies.
• Provide guidance on secure design, defense-in-depth, Zero Trust principles, and cybersecurity best practices.
• Prepare technical reports, engineering recommendations, risk assessments, and executive briefings.

Salary Range: Approximately $103,000.00 - $121,000.00/year. Minimum Qualifications

• Clearan ce Required
• Active Top Secret
• Education Requirements
• Bachelor's degree in Cybersecurity, Computer, Electrical, or Electronics Engineering, or Mathematics with a concentration in Computer Science; or a related discipline. The degree program must be accredited by ABET.
• Experience Requirements
• Minimum three (3) years of experience developing, implementing, and maintaining cybersecurity policies, including Assessment and Authorization (A&A) activities.
• Certification Requirements
• Must hold a DoD 8570/8140 Level I certification in IAM, IAT, or IASAE. Desired Qualifications
• Government & Compliance
• DoD/IC Experience: Experience supporting DoD, Intelligence Community, or classified government systems.
• RMF Expertise: Demonstrated experience engineering NIST RMF controls and producing RMF artifacts. Security Architecture & Engineering
• Secure Systems Design: Strong understanding of secure systems engineering, defense-in-depth, Zero Trust architectures, and large-scale distributed systems.
• Core Technologies: Experience with operating systems, networking, virtualization, cloud, IAM, encryption, and cybersecurity technologies.
• Vulnerability Management: Experience conducting vulnerability assessments using ACAS, Nessus, SCAP, or similar tools. Cloud & DevSecOps
• Modern Environments: Experience supporting cloud security, hybrid environments, containers, Kubernetes, or DevSecOps pipelines.
• Automation & Architecture: Familiarity with IaC/scripting (PowerShell, Python, Ansible, Terraform) and the DoD Enterprise DevSecOps Reference Design or Platform One. Professional Skills & Certifications
• Certifications: Active security certifications (e.g., Security+, CISSP, CASP+, CCSP, GIAC, or IASAE).
• Communication: Strong technical writing and verbal skills to convey complex cybersecurity concepts to both technical and leadership audiences.

About Us Formed through the strategic union of Sev1Tech and ERT, Entarian is a premier provider of mission-critical engineering and technology solutions. Founded on a legacy of excellence dating back to 1993, Entarian is a product of an evolved and fully diversified engineering and federal technology leader. From deep space to defense and civilian missions, Entarian delivers secure, mission-aligned digital solutions that drive national resilience and operational effectiveness. We don't just support modernization; we define it.

Join the Mission and Start your Career Journey: Apply Directly via our Careers Portal Connect, Referrals & Inquiries? Email the team: Entarian is an Equal Opportunity and Affirmative 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.