Lead Information Systems Security Engineer (ISSE) - TS/SCI with Polygraph

Clearance Level Must Currently Possess:

Clearance Level Must Be Able to Obtain:

Job Family:

Job Description:

Transform technology into opportunity as a Lead Information Systems Security Engineer (ISSE) with GDIT. A career in enterprise IT means connecting and enhancing the systems that matter most. At GDIT you’ll be at the forefront of innovation and play a meaningful part in improving how agencies operate. At GDIT, people are our differentiator. As a Lead Information Systems Security Engineer (ISSE) you will help ensure today is safe and tomorrow is smarter.

• Serve as the lead engineer for security accreditation, guiding ISSMs, SCAs, PMs, and engineering teams through the entire RMF/ICD 503 lifecycle.
• Drive systems to achieve ATD → IATT → ATO, ensuring technical and documentation readiness at each gate.
• Act 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 in‑depth technical reviews of system architectures and document security-relevant components for SSPs and CONOPS.
• Lead the development, review, and execution of all RMF/ICD 503 documentation, including SSP, 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 Information Systems Continuous Monitoring (ISCM) activities, performing technical content reviews and recommending improvements.

• 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, delivering concise, actionable recommendations.
• Ensure ongoing compliance and readiness through proactive security oversight and risk assessments.

• Required Education and Experience: Technical Training, Certification(s) or Degree + 10 years
• 10+ years of cybersecurity, information assurance, or security engineering experience.    
• Cleareance: Active TS/SCI with Polygraph
• Certification Required: DoD Manual 8570.01-M 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 IC 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.
• Location: On Customer Site

PREFERRED QUALIFICATIONS:

• Experience supporting DoW 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

GDIT IS YOUR PLACE: 

• 401K with company match 

• Comprehensive health and wellness packages 

• Internal mobility team dedicated to helping you build your skills and own your career 

• Professional growth opportunities including paid education and certifications 

• Cutting-edge technology you can learn from

• Rest and recharge with paid vacation and 10 company-paid holidays  

Scheduled Weekly Hours:

Work Location:

Additional Work Locations:

gdit.com/tc.