Lead Information Systems Security Engineer (ISSE) - TS/SCI with Polygraph
About The Position
GDIT is seeking a Lead Information Systems Security Engineer (ISSE) to lead security accreditation and engineering for customer systems. The role guides ISSMs, SCAs, project managers, and engineering teams through the RMF/ICD 503 lifecycle and drives systems toward ATD, IATT, and ATO while ensuring technical and documentation readiness. The ISSE serves as the primary contact for customer security organizations, audit teams, and senior leadership, and provides technical oversight and mentorship across projects. The position involves reviewing system architectures, documenting security-relevant components, and leading the development, review, and execution of RMF/ICD 503 documentation, including SSPs, CONOPS, contingency plans, user guides, and SOPs. The engineer updates control volatility assessments, supports Information Systems Continuous Monitoring (ISCM), tracks A&A progress, owns POA&M development and mitigation strategies, collects evidence, supports audits, and maintains compliance through proactive security oversight and risk assessments. The role is performed onsite at the customer location in Washington, DC.
Requirements
- 10 or more years of cybersecurity, information assurance, or security engineering experience.
- Technical training, certification(s), or a degree, plus 10 years of experience.
- Active TS/SCI clearance with Polygraph.
- U.S. citizenship.
- DoD Manual 8570.01-M certification at the Information Assurance System Architects & Engineer (IASAE Level II) role.
- Experience mentoring or leading security teams.
- Direct experience leading A&A/ATO efforts for large or complex systems.
- Mastery of RMF, ICD 503, and Intelligence Community accreditation processes.
- Strong technical writing expertise, especially in SSPs, CONOPS, POA&Ms, and audit documentation.
- Ability to translate complex engineering details into security artifacts and briefings.
Nice To Haves
- Experience supporting Department of War or Intelligence Community customers.
- Background in secure systems architecture or engineering.
- Familiarity with high-value assets, cross-domain systems, or TS/SCI mission systems.
- Experience leading A&A for Special Access Programs.
Responsibilities
- Lead security accreditation and guide ISSMs, SCAs, project managers, and engineering teams through the RMF/ICD 503 lifecycle.
- Drive systems to achieve ATD, IATT, and ATO while ensuring technical and documentation readiness.
- Serve as the primary point of contact for customer security organizations, audit teams, and senior leadership.
- Mentor junior engineers and provide technical oversight across multiple projects.
- Conduct technical reviews of system architectures and document security-relevant components for SSPs and CONOPS.
- Lead development, review, and execution of RMF/ICD 503 documentation, including SSPs, CONOPS, contingency plans, user guides, and SOPs.
- Review and update control volatility assessments based on evolving threats, IC policies, federal standards, and system sensitivity levels.
- Support ISCM activities through technical content reviews and recommendations for improvement.
- Track, document, and communicate A&A progress across multiple systems to customer leadership.
- Own POA&M development, mitigation strategies, and evidence collection from system owners and engineers.
- Provide audit liaison support for internal and external audits and deliver actionable recommendations.
- Ensure ongoing compliance and readiness through security oversight and risk assessments.
Benefits
- 401(k) with company match.
- Comprehensive health and wellness packages, including medical, dental, and vision plan options.
- Internal mobility team dedicated to helping employees build skills and careers.
- Professional growth opportunities, including paid education and certifications.
- Cutting-edge technology and learning opportunities.
- Paid vacation and 10 company-paid holidays.
- Flexible work weeks where possible.
- Paid time off plans including vacation, sick, personal, parental, military, bereavement, and jury duty leave.
- Short- and long-term disability benefits, life insurance, and other insurance offerings.
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What This Job Offers
Job Type
Full-time
Career Level
Senior
Education Level
No Education Listed
