Windows Systems Administrator

Description Position Overview We are seeking a Senior Infrastructure Engineer to support and operate mission-critical, enclave-based environments across on-premises VMware infrastructure and AWS cloud . This role sits at the center of a high-security, high-availability ecosystem , supporting systems where downtime has real operational impact . You will be responsible for owning, stabilizing, and improving a complex hybrid environment consisting of both legacy and modern platforms . This is not a passive support role-this is for someone who can step in, take control of the environment , and drive reliability and performance forward . Clearance Requirement Active TS/SCI with Poly security clearance required Must be eligible to work in restricted / air-gapped environments What You'll Own Two standalone/enclave Windows domains : On-prem VMware-based infrastructure AWS-hosted environment A 24/7 mission-critical system footprint Core enterprise services: identity, storage, compute, backup, and security tooling Environments with limited external connectivity and strict security controls Key Responsibilities Administer and maintain Windows-based infrastructure across enclave environments Manage VMware vCenter / ESXi (host performance, VM lifecycle, resource optimization) Support AWS cloud infrastructure (EC2, VPC, storage, IAM fundamentals) Maintain and troubleshoot Active Directory, Group Policy, and identity systems Oversee patching and system compliance via WSUS and SCCM Administer Microsoft Exchange and Citrix environments Maintain DNS, networking, and core infrastructure services Support and optimize SAN storage environments Manage backup and recovery operations using Rubrik Support and troubleshoot security platforms , including: Trellix ePO Rapid7 Security Onion IDS Centrify Perform deep-dive troubleshooting and root cause analysis across systems Maintain system documentation, SOPs, and incident response procedures Identify and implement infrastructure improvements and automation opportunities Environment Characteristics Air-gapped / enclave networks Hybrid on-prem (VMware) + AWS cloud Legacy mission systems with modernization constraints Security-first architecture with strict compliance requirements High uptime expectations with minimal tolerance for disruption Required Qualifications Must have at least 12 years of experience in systems engineering or infrastructure engineering Active TS/SCI with Poly Strong experience supporting Windows enterprise environments Proven experience in high-availability / mission-critical systems Experience operating in restricted, regulated, or air-gapped environments Strong troubleshooting skills across OS, virtualization, networking, and storage layers Ability to work independently and take ownership of complex systems Core Technical Expertise Operating Systems Windows Server (2016/2019/2022) Windows 11 Linux (Rocky Linux, Red Hat) Virtualization & Cloud VMware vCenter / ESXi AWS (EC2, VPC, storage, IAM basics) Core Infrastructure Active Directory & Group Policy DNS / networking fundamentals SAN Storage Systems Management

SCCM, WSUS

Microsoft Exchange Citrix Security Tooling Trellix ePO Rapid7 Security Onion IDS Centrify Backup & Recovery Rubrik Preferred PowerShell / Bash scripting Experience with compliance frameworks (STIGs, RMF, NIST) Operational Expectations Support a 24/7 operational environment Participate in a rotational on-call schedule Must be able to respond (Return-to-Base) within 2 hours , including travel if required Support after-hours maintenance windows and incident response What Sets This Role Apart Direct ownership of mission-critical systems supporting real-world operations Opportunity to work in secure, high-impact environments Exposure to both legacy infrastructure challenges and modernization efforts Ability to drive meaningful improvements , not just maintain status quo Who We're Looking For An engineer who: Has operated in cleared environments and understands the constraints Can walk into a complex, imperfect system and make it better Doesn't wait for direction•identifies problems and solves them Is trusted to handle high-pressure situations without supervision Brings both technical depth and operational accountability Bottom Line If you're looking for a role where: Your work directly supports critical operations You have real ownership and responsibility And your impact is immediate and visible 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 17, 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 $116,350.00•$210,325.00 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. About Leidos Leidos is an industry and technology leader serving government and commercial customers with smarter, more efficient digital and mission innovations. Headquartered in Reston, Virginia, with 47,000 global employees, Leidos reported annual revenues of approximately $16.7 billion for the fiscal year ended January 3, 2025. For more information, visit www.

Leidos.com . Pay and Benefits Pay and benefits are fundamental to any career decision. That's why we craft compensation packages that reflect the importance of the work we do for our customers. Employment benefits include competitive compensation, Health and Wellness programs, Income Protection, Paid Leave and Retirement. More details are available at www.leidos.com/careers/pay-benefits . Securing Your Data Beware of fake employment opportunities using Leidos' name. Leidos will never ask you to provide payment-related information during any part of the employment application process (i.e., ask you for money), nor will Leidos ever advance money as part of the hiring process (i.e., send you a check or money order before doing any work). Further, Leidos will only communicate with you through emails that are generated by the Leidos.com automated system•never from free commercial services (e.g., Gmail, Yahoo, Hotmail) or via WhatsApp, Telegram, etc. If you received an email purporting to be from Leidos that asks for payment-related information or any other personal information (e.g., about you or your previous employer), and you are concerned about its legitimacy, please make us aware immediately by emailing us at LeidosCareersFraud@leidos.com . If you believe you are the victim of a scam, contact your local law enforcement and report the incident to the U.S. Federal Trade Commission . Commitment to Non-Discrimination All qualified applicants will receive consideration for employment without regard to sex, race, ethnicity, age, national origin, citizenship, religion, physical or mental disability, medical condition, genetic information, pregnancy, family structure, marital status, ancestry, domestic partner status, sexual orientation, gender identity or expression, veteran or military status, or any other basis prohibited by law. Leidos will also consider for employment qualified applicants with criminal histories consistent with relevant laws.