Windows Systems Administrator

About this role

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: September 2, 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 agreeme

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