Leidos is seeking an experienced Senior System Administrator with team leadership and Microsoft Exchange skills to support the DTRA I3TS Infrastructure Services team to support, maintain and optimize critical mission operations across multiple geographic locations. The ideal candidate will be a technical expert responsible for installation, configuration, security, operation, and maintenance of servers, equipment, and software related to Microsoft Windows server and Exchange.

Candidates must demonstrate a high degree of problem-solving ability in a complex environment and be able to communicate effectively, both to the customer and to team members.

Primary Responsibilities:

• Lead a team of seven or more System Administrators with Windows expertise to fulfill DoW customer requirements in a fast-paced, challenging work environment

• Perform OS installation, configuration, hardening, and patching in compliance with DoD STIGs and agency policies.

• Monitor and tune system performance, conduct root cause analysis, and resolve complex issues quickly and efficiently.

• Oversee and maintain automation scripts and infrastructure as code (Ansible, PowerShell, Bash, etc.).

• Implements Windows based security, including but not limited to group permissions, file / folder permissions, group policies, local security policies, etc.

• Manage user accounts, credentials, permissions, access rights, storage allocations, and active directory administration.

• Monitor system performance and respond to alerts.

• Coordinate with customers and stakeholders to collect data, conduct analysis, develop, and implement solutions associated with incident tickets and requirements.

• Design, implement, and maintain Active Directory enterprise environments including:

• Active Directory Domain Services (AD DS).

• Group Policy design and governance.

• DNS and DHCP services.

• Directory replication and trust models.

• Install, configure, and upgrade Exchange Server environments and Active Directory.

• Monitoring server health, mail flow, and database integrity to ensure high availability.

• Create/manage mailboxes, shared mailboxes, distribution groups, and manage user access and permissions.

• Resolve complex email, mail routing, and client connectivity issues.

• Be able to work in a fast-paced environment and must be able to work independently.

• Work on multiple projects, leading projects that fall within the Area of responsibility.

• Communicate with internal team members across multiple areas and client team members.

• Provide support on a M-F business hours schedule, also responsible for on-call, extended hour, and weekend support as required by mission or emergency situations.

• Create, maintain, and implement detailed documentation and maintain standard operating procedures.

Basic Qualifications:

• BS with 8-10 years, or MS degree with 6-8 years of experience in IT operations working with Windows, Linux servers and Virtualization.

• Must hold a Top Secret/SCI Clearance.

• Experience administering Microsoft Exchange Server.

• Strong experience implementing and maintaining Security Technical Implementation Guides (STIGs).

• Document STIG configurations and remediation actions to ensure audit readiness.

• Conduct regular STIG compliance checks using tools like SCAP Compliance Checker and STIG Viewer.

• Proficiency in PowerShell scripting and automation.

• Strong problem-solving, analytical skills, and ability to work independently or in a team.

• Hands-on experience administering Windows network environments.

• DoD 8570 IAT Level II or III certification (e.g., Security+ CE, CASP+, CISSP).

• Experience supporting IC or DoD classified environments.

Preferred Qualifications:

• Microsoft certifications (MCSA, MCSE, Azure Administrator Associate)

• Experience with automation and scripting (Ansible, Bash, PowerShell, Python).

• Expert level knowledge on Active Directory, DNS, DHCP, Group Policy Object (GPO), Microsoft Clustering, domain architecture and performance tuning.

• Working knowledge of virtualization, VMWare, or equivalent.

• Experience supporting classified networks or cross-domain environments

If you're looking for comfort, keep scrolling. At Leidos, we outthink, outbuild, and outpace the status quo — because the mission demands it. We're not hiring followers. We're recruiting the ones who disrupt, provoke, and refuse to fail. Step 10 is ancient history. We're already at step 30 — and moving faster than anyone else dares.

Original Posting:

April 8, 2026

For U.S. Positions: While subject to change based on business needs, Leidos reasonably anticipates that this job requisition will remain open for at least 3 days with an anticipated close date of no earlier than 3 days after the original posting date as listed above.

Pay Range:

Pay Range $92,300.00 - $166,850.00

The Leidos pay range for this job level is a general guideline only and not a guarantee of compensation or salary. Additional factors considered in extending an offer include (but are not limited to) responsibilities of the job, education, experience, knowledge, skills, and abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law.