IT System Administrator; Fuse Fed

We are building one of the most potentially consequential companies of the century. Our mission is to accelerate the world's transition to fusion energy while safeguarding humankind. This is not a normal company. This is not a normal job. We are committed for the long term to win.

We're looking for an IT Administrator to support a growing team delivering testing services to DoD, USG, and commercial clients. This is a dual-scope role: you'll own day-to-day IT administration and help desk support within our Microsoft 365 GCC High environment, and you'll also own the governance, risk, and compliance (GRC) documentation (System Security Plan (SSP), Plan of Action and Milestones (POA&M), and control-implementation evidence) that supports our NIST SP 800-171 / CMMC program.

• Obsess about the details — sloppy work costs us later, so do it right the first time.

• Care — pick up the trash. Do things no one asks you to do. Go the extra mile because you care.

• Act with urgency — every hour matters more than it feels like it does.

• Be responsible for the outcome, not just the task; if it is not working, it remains your problem until it is fixed.

• Assume good intent — disagree openly, then commit fully once a call is made.

IT Administration

• Administer our Microsoft 365 GCC High tenant, including user identity, mailboxes, licensing, and access management.

• Manage and support a mixed fleet of macOS and Windows endpoints, including device provisioning, patching, and compliance configuration.

• Provide help desk support and troubleshooting for end users, resolving hardware, software, and connectivity issues.

• Manage user onboarding and offboarding, ensuring timely and accurate provisioning/deprovisioning of accounts and access.

• Serve as the local point of contact for our managed security services provider (MSSP), coordinating on SOC monitoring, alert triage, and log/data access needed for 24/7 security monitoring of the environment.

CMMC / GRC

• Own and maintain the System Security Plan (SSP) and Plan of Action and Milestones (POA&M) for our NIST SP 800-171 / CMMC program.

• Collect, organize, and maintain control-implementation evidence across technical, administrative, and physical controls.

• Translate MSSP guidance and assessment findings into concrete documentation updates and remediation tracking.

• Support policy development, review, and lifecycle management (drafting, versioning, approval tracking).

• Prepare documentation and evidence packages ahead of the mock assessment and final CMMC assessment.

• Track remediation items to closure and maintain an audit trail of compliance activities.

• Assist with scoping and boundary documentation for the CUI environment, including the separation between our environment and our parent company's systems.

• Hands-on administrative experience with Microsoft 365 GCC High (or GCC) environments.

• Working knowledge of NIST SP 800-171 controls, both as applied to IT administration and as documented for CMMC compliance.

• Experience managing and supporting both macOS and Windows endpoints in a business environment.

• Demonstrated help desk/end-user support and troubleshooting experience.

• Strong written documentation skills — able to translate technical controls into clear, assessor-ready language (SSP, POA&M, or equivalent).

• Experience organizing and maintaining audit or compliance evidence.

• Ability to obtain a Top Secret (TS) security clearance (U.S. citizenship required).

• Experience administering or supporting classified enclave networks.

• Direct experience supporting a CMMC Level 2 assessment (mock or final) or a NIST SP 800-171 self-assessment.

• Experience working with a C3
  
  PAO or third-party assessor.

• Experience…