Information System Security Engineer (ISSE)

Protect the systems that enable mission success. NS2 Mission is seeking an experienced Information Systems Security Engineer (ISSE) to support our team in Chantilly, VA. In this role, you'll help ensure the security, compliance, and accreditation of mission-critical systems across enterprise and cloud environments. Working closely with engineering teams, ISSMs, and government stakeholders, you'll guide systems through the Risk Management Framework (RMF) lifecycle while helping maintain a strong security posture in support of customer mission objectives.

If you're passionate about cybersecurity, system accreditation, and enabling secure technology solutions, we'd love to hear from you.

Key Responsibilities

• Maintain and enhance the security posture of enterprise and cloud-based computing environments.
• Lead security accreditation efforts throughout the full system lifecycle in accordance with ICD 503 Rev. 4 and the Risk Management Framework (RMF).
• Develop, maintain, and update System Security Plans (SSPs) and other required security documentation.
• Partner with Information System Security Managers (ISSMs), engineers, and program leadership to ensure security compliance and accreditation readiness.
• Assess system risks, identify security gaps, and recommend mitigation strategies to maintain compliance.
• Interpret and apply Sponsor security policies, standards, and cybersecurity best practices.
• Support continuous monitoring activities and help ensure ongoing security compliance for mission systems.
• Collaborate with technical teams to integrate security requirements throughout the system development lifecycle.

Required Qualifications

• Senior-level experience supporting Information Systems Security Engineering activities.
• 5+ years of experience maintaining the security posture of enterprise and cloud computing environments.
• Experience managing security accreditation efforts under the ICD 503 Rev. 4 framework.
• Strong understanding of Sponsor information security policies and the Risk Management Framework (RMF).
• 5+ years of experience developing and maintaining System Security Plans (SSPs) and related security documentation.

Preferred Qualifications

• Experience working directly with Sponsor Information System Security Managers (ISSMs) to achieve and maintain system compliance.
• Experience obtaining Intelligence Community (IC) reciprocity for one or more security accreditations.
• Familiarity with continuous monitoring, vulnerability management, and security assessment activities.
• Experience supporting secure cloud environments and enterprise modernization initiatives.

Position Clearance Requirement:



TS/SCI with an FSP

Please be aware many of our positions require the ability to obtain or maintain a U.S security clearance which requires U.S citizenship.

We win with inclusion

NS2 Mission's culture of inclusion, focus on health and well-being, and flexible working models help ensure that everyone - regardless of background - feels included and can run at their best. At NS2 Mission, we believe we are made stronger by the unique capabilities and qualities that each person brings to our company, and we invest in our employees to inspire confidence and help everyone realize their full potential. We ultimately believe in unleashing all talent and creating a better world.

NS2 Mission is committed to the values of Equal Employment Opportunity and provides accessibility accommodations to applicants with physical and/or mental disabilities. If you are interested in applying for employment with NS2 Mission and are in need of accommodation or special assistance to navigate our website or to complete your application, please send an e-mail with your request to Recruiting Operations Team: NS2Mission.Careers@sapns2.com .

Qualified applicants will receive consideration for employment without regard to their age, race, religion, national origin, ethnicity, age, gender (including pregnancy, childbirth, et al), sexual orientation, gender identity or expression, protected veteran status, or disability, in compliance with applicable federal, state, and local legal requirements.