Systems Administrator - VMware & Virtualization | Top Secret w/SCI eligibility

Overview

American Systems is seeking a Sr. Systems Administrator with strong experience in network infrastructure, switching, and VMware virtualization to support, maintain, secure, and optimize enterprise IT systems.

This role is responsible for administering core infrastructure environments, including network switches, virtualized platforms, server systems, and cybersecurity controls. The ideal candidate combines hands-on systems administration expertise with strong networking knowledge and a security-first mindset.

Responsibilities

• Administer, maintain, and troubleshoot enterprise IT infrastructure, including servers, virtual environments, and network systems.

• Configure, manage, and support network switches, VLANs, trunking, port security, and related network services.

• Monitor and maintain LAN/WAN connectivity, network performance, and infrastructure availability.

• Deploy, administer and support VMware environments, including ESXi hosts, vCenter, virtual machines, storage connectivity, snapshots, patching, and performance tuning.

• Implement and maintain secure system configurations in accordance with company cybersecurity policies and best practices.

• Perform system hardening, patch management, vulnerability remediation, and access control administration.

• Support firewall, VPN, endpoint protection, and network access controls as needed.

• Manage Active Directory, group policies, DNS, DHCP, and other core infrastructure services.

• Respond to system alerts and outages; conduct root cause analysis and document corrective actions.

• Support backup, disaster recovery, and business continuity processes for critical systems.

• Maintain system documentation, network diagrams, standard operating procedures, and asset inventories.

• Assist with audits, compliance activities, and security assessments.

• Collaborate with IT, cybersecurity, and business teams on infrastructure upgrades, deployments, and operational improvements.

• Recommend improvements to system performance, reliability, and security posture.

Qualifications

• Active Top Secret clearance with SCI eligibility

• CompTIA Security+ certification

• 3+ years of experience in systems administration, network administration, or cyber infrastructure support.

• Hands-on experience with managed network switches and enterprise networking concepts.

• Strong experience with VMware vSphere, including ESXi and vCenter administration.

• Experience with Windows Server administration and core services such as Active Directory, DNS, DHCP, and Group Policy.

• Understanding of cybersecurity principles, system hardening, patching, vulnerability management, and secure access controls.

• Experience troubleshooting network connectivity, switching, and virtualization issues.

• Familiarity with backup and recovery tools, monitoring platforms, and automation/scripting.

• Strong analytical, troubleshooting, and documentation skills.

• Ability to work independently and collaboratively in a fast-paced environment.

Technical Skills

• VMware ESXi, vCenter, VM provisioning and administration

• Network fundamentals including network switching and routing, VLANs, STP, trunking, port security, TCP/IP, DNS, DHCP, and VPN

• Windows Server administration

• Active Directory and Group Policy

• System monitoring and log review

• Patch management and vulnerability remediation

• Backup and disaster recovery

• Cybersecurity best practices and secure configuration management

Soft Skills

• Strong problem-solving and critical thinking

• Clear written and verbal communication

• Ability to prioritize and manage multiple tasks

• Strong customer service and teamwork mindset

• Attention to detail and commitment to secure operations

Preferred Qualifications

• Experience with Cisco, Dell, Aruba, Juniper, or similar enterprise switching platforms.

• Bachelor’s degree in Information Technology, Cybersecurity, Computer Science, or related field preferred; or equivalent combination of education and experience.

• Industry certifications such as:

• Network+

• CCNA

• VMware VCP

• Microsoft or other relevant infrastructure certifications

• Experience with firewalls, IDS/IPS, SIEM, or endpoint detection and response tools.

• Familiarity with scripting or automation using PowerShell, Python, or similar tools.

• Experience supporting regulated or compliance-driven environments.

Work Environment

• All work will take place on-site

• May occasionally require after-hours support for system maintenance

#LI-PR

Pay Transparency Statement AMERICAN SYSTEMS is committed to pay transparency for our applicants and employee-owners. The salary range for this position is USD $110,000.00/Yr. - USD $150,000/Yr. Actual compensation will be determined based on several factors permitted by law. AMERICAN SYSTEMS provides for the welfare of its employees and their dependents through a comprehensive benefits program by offering healthcare benefits, paid leave, retirement plans, insurance programs, and education and training assistance. EEO Statement EEO Race/Sex/Disability Status/Veteran Status