Senior System Administrator

Join Radiant, a company focused on commercializing the first mass-produced nuclear reactor. As a Senior Systems Administrator, you will be responsible for managing Microsoft 365 GCC High, building identity and access automation, and overseeing endpoint, email security, and SaaS infrastructure. You will also implement technical controls for the CMMC assessment and take new platform projects from idea to deployment. This role offers substantial equity, comprehensive medical and dental coverage, flexible PTO, and a beautiful headquarters in El Segundo, California.

• Assumer la responsabilité de l'administration et de la configuration de Microsoft 365 GCC High, y compris Exchange Online, SharePoint, Teams et la configuration du locataire.
• Développer et mettre en œuvre l'automatisation de l'identité et de l'accès dans un environnement natif Entra, y compris le cycle de vie des employés, les droits d'accès et les examens d'accès.
• Gérer la sécurité des e-mails et la protection des informations, y compris Defender for Office, le flux de messagerie et la posture anti-phishing.

• Deep, hands-on experience across the responsibilities above: GCC High tenant administration, Entra, self-built IAM automation, Intune without Group Policy, email security and Purview, and SaaS/AWS administration
• Service is the job; tier-1 handles day-to-day support, but nobody's too senior to help the person at their desk
• 7+ years administering and engineering production systems
• Bachelor's degree in Information Technology, Computer Engineering, Cybersecurity, or a similar field (4 years of work experience in lieu of a degree)
• Solid networking fundamentals: VLANs, routing, firewall policy, DNS/DHCP, VPN, wireless
• Treats compliance control implementation and evidence collection as normal work
• Must be willing to work extended hours and weekends as necessary to accomplish our mission
• Deployed Box, Slack, or comparable platforms into a regulated environment and handled the data boundary questions
• Purview depth: DLP, sensitivity labeling, retention, or eDiscovery
• Automation experience with PowerShell, Python, Microsoft Graph, and infrastructure as code (Terraform, Bicep, or similar)
• Written and maintained PowerShell modules other people use, not just scripts
• CMMC or NIST 800-171 exposure; leading an assessment is not required
• Stood up identity governance tooling: Entra ID Governance, SailPoint, Okta Workflows, or equivalent