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

VulnU; Washington (District of Columbia); On-site; USD 164,000 - 207,000; Full time

Benefits offered by this job

401K with company match

Comprehensive health and wellness

Paid vacations and holidays

Job summary

GDIT is seeking a Lead Information Systems Security Engineer (ISSE) to drive RMF/ICD 503 accreditation and ATO for complex systems on-site in Washington, DC. You will mentor engineers, coordinate with customer security teams, and own POA&M development.

Required TS/SCI with Polygraph and IASAE II certification, plus 10+ years in cybersecurity and information assurance. The role emphasizes technical leadership and strong security documentation skills.

Qualifications

• Technical depth in information system security and risk management.
• Experience with RMF/ICD 503 processes and A&A artifacts.
• Strong written competencies for SSPs, CONOPS, and audit documentation.

Responsibilities

• Lead security accreditation activities across RMF/ICD 503 lifecycle.
• Coordinate with ISSMs, PMs, SCAs, and engineering teams to achieve ATO.
• Develop and review SSPs, CONOPS, POA&Ms, and audit evidence.
• Provide liaison for audits and mentor junior engineers.

Skills

Information System Security

POA&M

Risk Assessments

Job description

# Lead Information Systems Security Engineer (ISSE) - TS/SCI with PolygraphGDIT · gdit.comCategory: Security EngineeringLocation: USA DC WashingtonLevel: ManagerSalary: $164,382 – $207,000Clearance: TS/SCI + Poly## Quality of lifeWhat the posting states. Hover or tap a perk to see the line it came from.* Retirement match* Paid parental leaveType of Requisition:RegularClearance Level Must Currently Possess:Top Secret SCI + PolygraphClearance Level Must Be Able to Obtain:Top Secret SCI + PolygraphPublic Trust/Other Required:NoneJob Family:Cyber and IT Risk ManagementJob Qualifications:Skills:Information System Security, Plan of Action and Milestones (POA&M), Risk AssessmentsCertifications:NoneExperience:10 + years of related experienceUS Citizenship Required:YesJob 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.HOW A LEAD INFORMATION SYSTEMS SECURITY ENGINEER (ISSE) WILL MAKE AN IMPACT: Lead & OwnershipServe 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.Technical Security EngineeringConduct 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.A&A Execution and ComplianceTrack, 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.WHAT YOU’LL NEED TO SUCCEED:Required Education and Experience: Technical Training, Certification(s) or Degree 10 years10 years of cybersecurity, information assurance, or security engineering experience. Cleareance: Active TS/SCI with PolygraphCertification Required: DoD Manual 8570.01-M at the Information Assurance System Architects & Engineer (IASAE Level II) roleExperience 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 SitePREFERRED 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 ProgramsGDIT 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 fromRest and recharge with paid vacation and 10 company-paid holidays OWN YOUR OPPORTUNITY Explore a career in cyber at GDIT and you’ll find endless opportunities to grow alongside colleagues who share your focus on defending and protecting what matters.#VA\\_2026Alumni#MD\\_2026Alumni#GDITEnhanced2026#GDITCareers#JETThe likely salary range for this position is $164,382 - $207,000. This is not, however, a guarantee of compensation or salary. Rather, salary will be set based on experience, geographic location and possibly contractual requirements and could fall outside of this range.Scheduled Weekly Hours:40Travel Required:NoneTelecommuting Options:OnsiteWork Location:USA DC WashingtonAdditional Work Locations:Total Rewards at GDIT:Our benefits package for all US-based employees includes a variety of medical plan options, some with Health Savings Accounts, dental plan options, a vision plan, and a 401(k) plan offering the ability to contribute both pre and post-tax dollars up to the IRS annual limits and receive a company match. To encourage work/life balance, GDIT offers employees full flex work weeks where possible and a variety of paid time off plans, including vacation, sick and personal time, holidays, paid parental, military, bereavement and jury duty leave. To ensure our employees are able to protect their income, other offerings such as short and long-term disability benefits, life, accidental death and dismemberment, personal accident, critical illness and business travel and accident insurance are provided or available. We regularly review our Total Rewards package to ensure our offerings are competitive and reflect what our employees have told us they value most. Our Identity Verification Process:As part of the hiring process, we will ask you to complete an identity verification process that leverages advanced biometrics and artificial intelligence to ensure authenticity and protect against identity fraud. You are expected to be on camera during virtual interviews. We reserve the right to take your picture to verify your identity and prevent fraud. By proceeding, you authorize the collection, processing, and use of your biometric data for identity verification and security purposes. About Our Work:We are GDIT. A global technology and professional services company that delivers technology solutions and mission services to every major agency across the U.S. government, defense and intelligence community. Our 26,000 experts extract the power of technology to create immediate value and deliver solutions at the edge of innovation. We operate across 50+ countries worldwide, offering leading mission-ready capabilities in AI, cloud, cyber and software development.Join our Talent Community to stay up to date on our career opportunities and events atgdit.com/tc.Equal Opportunity Employer / Individuals with Disabilities / Protected Veterans—Curated listing: aggregated from GDIT's public careers page. Apply directly via the link — GDIT has not paid for placement.