Windows Systems Administrator

Senior Infrastructure Engineer

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.