M365 Admin & Security Operations Leader (Hybrid)

Three Saints Bay, LLC; Manassas (VA); Hybrid; USD 100,000 - 120,000; Full time

Job summary

Three Saints Bay, LLC is seeking an experienced 365 Admin and Help Desk Manager to lead IT operations with emphasis on Microsoft 365, endpoint management, security, and compliance with CMMC/NIST SP 800-171. Hybrid work options in Manassas, VA or Charleston, SC are available.

You will oversee Exchange Online, Teams, OneDrive, SharePoint Online, Defender, Sentinel, and Intune, while aligning policies to zero-trust and MFA requirements.

Qualifications

• Bachelor's degree in IT, CS, cybersecurity, or related field or equivalent experience.
• 7+ years IT experience with at least 4+ years in a managerial role.
• 5+ years hands-on experience administering M365 environments (E3/E5).

Responsibilities

• Lead the administration, configuration, and optimization of Microsoft 365 environments including Exchange Online, Teams, OneDrive, and SharePoint Online.
• Manage Intune for device enrollment, compliance, configuration, Autopilot, and security across devices.
• Oversee Defender for threat protection, vulnerability management, and incident response.
• Administer Sentinel for SIEM, threat hunting, analytics, and automated response workflows.
• Ensure IT systems comply with NIST SP 800-171 and CMMC Level 2+ requirements, including SSP and POA&M.
• Manage and mentor the help desk/support team, including staffing, training, and escalation.
• Provide advanced troubleshooting for M365 apps, device management, security alerts, and access issues.
• Develop IT policies aligned with zero-trust, MFA, DLP, and compliance frameworks.
• Monitor performance, security posture, and compliance metrics; report to leadership/auditors.

Skills

Leadership & team management

IT security operations

Policy development & compliance

End-user support & troubleshooting

Education

Bachelor's degree in Information Technology/CS/Cybersecurity

Tools

Exchange Online

SharePoint Online

Teams

OneDrive

Intune (Endpoint Manager)

Defender suite

Microsoft Sentinel

Azure Entra ID / Azure AD

Conditional access & MFA

NIST SP 800-171 / CMMC knowledge

Job description

Three Saints Bay, LLC is seeking an experienced 365 Admin and Help Desk Manager to lead IT operations with emphasis on Microsoft 365, endpoint management, security, and compliance with CMMC/NIST SP 800-171. Hybrid work options in Manassas, VA or Charleston, SC are available.

You will oversee Exchange Online, Teams, OneDrive, SharePoint Online, Defender, Sentinel, and Intune, while aligning policies to zero-trust and MFA requirements.