Senior Manager, Classified Networks Administration

Why Castelion, Why Now

Castelion is moving incredibly fast to develop and deliver advanced defense systems at a time when execution matters more than ever. We believe focus and technical excellence are decisive advantages - and we are building a team that can deliver real capability, not just concepts.

This is a rare opportunity to join at an early stage, where your work will directly shape critical systems, influence major technical decisions, and have immediate, real‑world impact.

Build, scale, and lead enterprise classified IT infrastructure across multiple secure facilities. Own strategy, architecture, deployment, and operations of classified network environments supporting mission‑critical defense programs. Partner closely with Engineering, Cybersecurity, Facilities, Security, and Program Management to deliver compliant, resilient infrastructure in a fast‑paced defense startup.

• Define and execute enterprise classified network strategy across multiple sites, labs, and manufacturing facilities.
• Design, implement, and operate infrastructure supporting Secret, Top Secret, SCI, and SAP environments.
• Oversee networking, compute, virtualization, storage, identity management, monitoring, and disaster recovery.
• Ensure compliance with RMF, NIST 800‑53, ICD 503, DISA STIGs, and Zero Trust principles; support ATOs and government accreditation activities.
• Drive infrastructure modernization through automation, Infrastructure as Code, and Dev Sec Ops  practices.
• Partner with engineering, program management, and executive leadership to align technology delivery with business growth.
• Manage infrastructure budgets, vendor relationships, and multi‑year technology roadmaps.
• Recruit, develop, and retain high‑performing technical talent across multiple locations.
• Support new facility stand‑ups, classified program starts, and proposal activities.

• Bachelor’s degree in Computer Science, IT, Engineering, or related field.
• 10+ years designing and operating enterprise infrastructure in classified environments.
• 5+ years leading technical teams across multiple sites.
• Experience in a defense contractor or government environment.
• Strong working knowledge of NIST SP 800‑53, RMF, DoD cybersecurity policy, Windows Server/AD, Linux, VMware, Cisco networking, and enterprise storage.
• Demonstrated success building and scaling IT organizations in high‑growth settings.
• Active Top Secret clearance; SCI eligibility required (CI Poly preferred). U.S. citizenship required.

• SAP and SCI environment experience.
• SCIF or classified facility stand‑up experience.
• Automation proficiency:
  Power Shell, Python, Terraform, or Ansible.
• Familiarity with Azure Government, AWS Gov Cloud, or hybrid classified cloud environments.
• Certifications:
  
  CISSP, CCNP/CCIE, VMware VCP, Azure Administrator, or equivalent.

• Establish scalable classified network infrastructure supporting multiple DoD programs.
• Achieve or maintain ATOs for critical classified systems.
• Build and develop a high‑performing classified IT team.
• Develop repeatable operational processes that support rapid company growth.

• Ability to put in extended hours, including evenings and weekends, when required to meet aggressive timelines
• This role is based in Torrance, CA and requires full‑time onsite presence

Please note this job description is not designed to cover or contain a comprehensive listing of activities, duties or responsibilities that are required of the employee for this job. Duties, responsibilities and activities may change at any time with or without notice.

All full‑time employees are granted meaningful long‑term equity, sharing in the company’s significant growth trajectory. We offer four (4) weeks of paid time off, ten (10) company‑paid holidays, and comprehensive health benefits – including 100% employee‑covered medical and strong dependent coverage, along with dental and vision plans. We also provide paid parental leave to support growing families, a $100 monthly fitness stipend to promote health and…