Senior Systems Administrator, Cross Domain (R4901)

Shield AI•Washington, DC

1d•Onsite

About The Position

We are seeking a highly motivated and skilled Cross Domain Solutions (CDS) Systems Administrator with 3–5 years of experience to join our Federal Systems Team as a key contributor to our high-performing Classified IT operations. This is an on-site role supporting mission-critical environments. The ideal candidate brings a strong aptitude for learning, an exceptional ability to troubleshoot complex systems, and a deep commitment to maintaining the integrity and security of classified environments. In this role, you will directly support Shield AI’s mission by ensuring the reliability, security, and compliance of systems that enable secure data transfer and interoperability across multiple security domains. As a CDS Systems Administrator, you will play a critical role in maintaining and supporting cross domain solutions that facilitate controlled information flow between networks of differing classification levels (e.g., Unclassified, CUI, Secret, and Top Secret). This includes enforcing strict security controls, supporting accreditation efforts, and ensuring systems operate in compliance with DoD and Intelligence Community standards.

Requirements

3–5 years Systems Administrator experience in classified environments.
Experience with Cross Domain Solutions or MLS environments.
Linux (Ubuntu/RHEL) and Windows Server experience.
Familiarity with RMF and NIST 800-53.
Networking experience (Cisco/Juniper/Palo Alto).
Security+ Certification

Nice To Haves

Experience with CDS tools (Radiant Mercury, Owl, Everfox, etc.)
Knowledge of Raise-the-Bar requirements
Scripting (PowerShell, Python, Bash)
Mixed OS environment experience
Bachelor’s degree or equivalent experience

Responsibilities

Administer, monitor, and maintain Cross Domain Solutions (e.g., guards, filters, data diodes, and transfer systems).
Support configuration, patching, auditing, and monitoring of CDS systems.
Troubleshoot CDS-related data flow issues.
Coordinate with cybersecurity and engineering teams.
Maintain classified and CUI systems ensuring availability and security.
Provide technical support for engineering and integration efforts.
Enforce security policies aligned with RMF and NIST standards.
Maintain accurate system documentation.
Support audit readiness and compliance requirements.
Assist with installation of servers, network equipment, and CDS appliances.
Perform system imaging and deployment.
Support design of classified systems and cross domain architectures.
Collaborate on secure integrations across classification levels.