Sr. Systems Engineer - Herndon, VA --TS/CI Poly

Type of Requisition:

Pipeline

Clearance Level Must Currently Possess:

Top Secret SCI + Polygraph

Clearance Level Must Be Able to Obtain:

Top Secret SCI + Polygraph

Public Trust/Other Required:

None

Job Family:

Systems Engineering

Job Qualifications:

Skills:

Complex Systems Design, Engineering, Systems Design

Certifications:

None

Experience:

5 + years of related experience

US Citizenship Required:

Yes

Job 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), cryptograp