Type of Requisition:PipelineClearance Level Must Currently Possess:Top Secret SCI + PolygraphClearance Level Must Be Able to Obtain:Top Secret SCI + PolygraphPublic Trust/Other Required:NoneJob Family:Systems EngineeringJob Qualifications:Skills:Complex Systems Design, Engineering, Systems DesignCertifications:NoneExperience:5 + years of related experienceUS Citizenship Required:YesJob Description:Deliver simple solutions to complex problems as a Systems Engineer Senior at GDIT. Here, you’ll tailor cutting-edge solutions to the unique requirements of our clients. With a career in application development, you’ll make the end user’s experience your priority and we’ll make your career growth ours.GDIT is seeking a highly experienced Senior Systems Engineer with a strong cybersecurity background to support, secure, and maintain classified systems. The position focuses on sustaining Cross-Domain Solutions (CDS) and messaging/reporting systems critical to secure information exchange across multiple classification levels. The ideal candidate will combine systems engineering expertise with cybersecurity best practices in classified environments to ensure system integrity, availability, and confidentiality.Key Responsibilities:Lead cybersecurity engineering efforts to protect CDS and encrypted messaging/reporting platforms in a classified environment.Implement and maintain system security controls in accordance with IC and DoD cybersecurity policies, including ICD 503, CNSSI 1253, NIST SP 800-53, and the Risk Management Framework (RMF).Support daily cybersecurity operations including system monitoring, incident response, vulnerability management, and remediation activities.Configure, maintain, and secure system components such as servers, databases, encryption devices, and secure communication channels.Ensure secure configuration, patch management, and hardening of operating systems (Linux/Windows) and application layers.Conduct risk assessments, threat modeling, and security impact analyses for CDS and encrypted communication systems.Collaborate closely with cybersecurity teams, network engineers, ISSOs, and vendors to resolve security incidents and implement mitigation strategies.Maintain and update security documentation, including System Security Plans (SSP), Security Assessment Reports (SAR), and Standard Operating Procedures (SOPs).Lead system audits, support Authority to Operate (ATO) renewals, and assist with continuous monitoring requirements.Mentor and guide junior engineers on cybersecurity practices, secure system operation, and classified environment protocols.Participate in system integration, testing, and validation to ensure cybersecurity requirements are met.Support mission partners by providing cybersecurity expertise during operational and emergency situations.Required Qualifications:Active TS/SCI with CI Poly (must be adjudicated and in scope).Bachelor’s degree in Cybersecurity, Systems Engineering, Computer Science, or related technical field (or equivalent experience).8+ years of experience in systems engineering with a focus on cybersecurity within classified IC or DoD environments.Demonstrated experience supporting or securing Cross-Domain Solutions (CDS) and encrypted messaging/reporting systems.Deep understanding of classified network architectures, secure data flows, and encryption technologies.Strong proficiency with operating systems (Linux and Windows), system hardening, patch management, and security configuration.Experience applying RMF and NIST cybersecurity frameworks to classified systems.Proven skills in vulnerability assessment tools, intrusion detection/prevention systems, and incident response.Familiarity with IC cybersecurity policies and directives, including ICD 503, CNSSI 1253, and cross-domain risk management.Excellent troubleshooting and problem-solving skills in complex, multi-domain environments.Strong communication skills with the ability to document technical findings clearly and coordinate with multidisciplinary teams.Preferred Qualifications:Certifications such as CISSP, Security+, GCIH, GCIA, CEH, or equivalent.Experience with NSA-approved CDS platforms (Radiant Mercury, GuardX, Owl, etc.).Knowledge of Public Key Infrastructure (PKI), cryptographic standards, and secure messaging protocols.Experience with system automation, scripting (Python, PowerShell, Bash), and cybersecurity tools.Familiarity with classified cloud environments (C2S, SC2S) and virtualization technologies.Prior experience working in a SCIF and adhering to IC physical and operational security controls.GDIT IS YOUR PLACE: 401K with company match Comprehensive health and wellness packages Internal mobility team dedicated to helping you 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 holidays.The likely salary range for this position is $119,850 - $162,150. 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:10-25%Telecommuting Options:OnsiteWork Location:USA VA HerndonAdditional 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.We are GDIT. A global technology and professional services company that delivers consulting, technology and mission services to every major agency across the U.S. government, defense and intelligence community. Our 30,000 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 capabilities in digital modernization, AI/ML, Cloud, Cyber and application development. Together with our clients, we strive to create a safer, smarter world by harnessing the power of deep expertise and advanced technology.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