Systems Engineer – Microsoft 365 Security & Compliance / Endpoint Security Engineer (GCC)

Job overview

Systems Engineer – Microsoft 365 Security & Compliance / Endpoint Security Engineer (GCC). This is an onsite position in Oxon Hill, MD. The salary range is $107,900.00 - $195,050.00 per year. Leidos is seeking an experienced M365 Security and Compliance Administrator. This role is responsible for securing and maintaining compliance of the Microsoft 365 (M365) ecosystem and enterprise endpoints. It leads security governance, implements and enforces controls across M365, email, identity, devices, and telemetry, and provides incident response and audit/ATO support.

What you'll do

• Lead the development, implementation, and ongoing management of M365 security policies, standards, and technical guardrails
• Own governance for data protection capabilities
• Define and enforce email security policies
• Implement and maintain email encryption solutions
• Administer and monitor anti-spam, anti-phishing, and anti-malware protections
• Engineer and validate device-compliance–based Conditional Access policies
• Investigate and remediate Conditional Access failures, identity anomalies, and external/guest access issues
• Design, test, and deploy Intune configuration and compliance policies
• Develop remediation scripts
• Coordinate enterprise rollout of urgent vulnerability mitigations and validated vendor fixes
• Establish and operate a risk management approach
• Support ATO/control assessment activities
• Lead integration and operational management of Microsoft Defender and Microsoft Sentinel
• Build and maintain SIEM integrations/connectors
• Tune audit retention, analytic rules, and alert logic
• Provide Tier 3 troubleshooting for device compliance failures, identity/access incidents, telemetry gaps, and OS/app protection issues
• Partner with cross-functional teams
• Stay current on M365 security/compliance updates, industry trends, and emerging capabilities.

What we're looking for

Education

Expert-level technical skills

Experience

Expert-level Intune engineering across Windows/macOS/iOS/iPadOS; Advanced PowerShell for remediation, automation, and OS image manipulation; Deep experience with Microsoft Defender (XDR, Endpoint, Cloud Apps); Hands-on with Sentinel SIEM, Function Apps, and cross-platform telemetry pipelines; Strong understanding of CAP architecture and identity risk enforcement; Experience with ATO control evidence, compliance mapping, and audit support.

Skills & competencies

systems engineer

microsoft 365

security

compliance

endpoint security

gcc

leidos

oxon hill md

united states

full time

it

m365

intune

defender

sentinel

entra id

conditional access

powershell

ato

About the employer

Leidos is hiring for this role. Industry: Commercial and Industrial Machinery and Equipment (except Automotive and Electronic) Repair and Maintenance. Sector: 81.