Senior M365 Security & Compliance Engineer

Leidos; Washington (District of Columbia); On-site; USD 120,000 - 170,000; Full time

Job summary

Leidos is seeking an experienced M365 Security and Compliance Administrator to join our Information Technology team. The role focuses on securing and maintaining compliance of the Microsoft 365 ecosystem and enterprise endpoints across Windows, macOS, and mobile platforms.

You will lead security governance, implement controls across M365, email, identity, devices, and telemetry, and provide incident response and audit support to ensure alignment with federal requirements.

Qualifications

• 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.

Responsibilities

• Lead the development, implementation, and ongoing management of M365 security policies, standards, and guardrails aligned to federal requirements and organizational controls.
• Own governance for data protection capabilities including document classification, labeling, retention, and DLP using Microsoft Purview.
• Define and enforce email security policies such as encryption, labeling, and secure mail flow to reduce data leakage.
• Implement and maintain email encryption solutions to protect confidentiality of email communications.
• Administer and monitor anti-spam, anti-phishing, and anti-malware protections.
• Engineer and validate device‑compliance‑based Conditional Access policies across Windows, macOS, and mobile platforms.
• Investigate and remediate Conditional Access failures, identity anomalies, and external/guest access issues.

Skills

Intune engineering

PowerShell scripting

Microsoft Defender

Sentinel SIEM

CAP architecture

ATO evidence & audit support

Tools

Jamf

Okta connectors

Copilot audit logging

Microsoft Graph API

mSCP baseline engineering

Job description

Leidos is seeking an experienced M365 Security and Compliance Administrator to join our Information Technology team. The role focuses on securing and maintaining compliance of the Microsoft 365 ecosystem and enterprise endpoints across Windows, macOS, and mobile platforms.

You will lead security governance, implement controls across M365, email, identity, devices, and telemetry, and provide incident response and audit support to ensure alignment with federal requirements.