Senior System Administrator | TS/SCI Polygraph

Cornerstone Defense LLC; Annapolis (MD); On-site; USD 190,000 - 210,000; Full time

Benefits offered by this job

Medical, Dental and Vision Plans

Generous PTO Policy

401(k)

HSA and FSA options

Life and Disability Insurance

Tuition Reimbursement and Training

Perks at Work Discount Program

Referral Program

Leads Generation Program

CollegeAmerica 529

Fitness Reimbursement Program

Travel Assistance

Norton Lifelock Benefit Solutions

Life Planning Financial & Legal

Job summary

Cornerstone Defense LLC is seeking a Senior System Administrator in Annapolis Junction, MD, offering a $190K–$210K compensation and Active TS/SCI w/ Polygraph clearance. You will support secure enclave development networks, conduct testing, maintain SOPs, manage accounts, and ensure baseline security in a collaborative, small-team environment.

Required: technical degree and 15+ years or equivalent. Expertise in Windows Server, AD, Group Policy, Linux, NetApp, and VMware stacks.

Qualifications

• Bachelor's degree in a technical discipline and 15 years' experience as a System Administrator, OR High school diploma and 20 years' experience as a System Administrator
• Experience with Windows Server Administration, Active Directory, and Group Policy
• Familiarity with Linux Server Administration
• Familiarity with Broadcom VMware/ESXi, Broadcom VMware Virtual Networking, and Broadcom VMware vCenter
• Networking Switching and Router Management
• Storage Management (NetApp)
• Hardware and OS troubleshooting
• System hardening
• Security Compliance Scanning (Nessus, ACAS)
• Understanding RMF security design requirements
• Active DoD IAT Level II certification (Security+)
• Excellent attention to detail and problem solving

Responsibilities

• Conduct functional and connectivity testing to ensure operability
• Develop and document system administration SOPs
• Maintain baseline system security per policies
• Manage accounts, rights, and access to systems
• Plan, execute, and verify data redundancy and recovery procedures
• Install, update, and troubleshoot systems and servers
• Comply with SOPs and security policies
• Enforce local network usage policies and procedures
• Manage system resources including performance and capacity
• Monitor and maintain system/server configurations
• Repair faulty system/server hardware
• Troubleshoot hardware/software interface and interoperability problems

Skills

Windows Server Admin

Active Directory

Group Policy

Linux Server Admin

Broadcom VMware/ESXi

VMware vCenter

PowerCLI

Networking Switching/Router

Storage NetApp

Security Compliance RMF

DoD IAT Level II (Security+)

Education

Bachelor's degree in technical discipline

15+ years System Admin experience OR High school diploma + 20 years

Tools

Broadcom VMware/ESXi

Broadcom VMware Aria Suite

Broadcom VMware Cloud Foundation (VCF)

Job description

Cornerstone Defense LLC is seeking a Senior System Administrator in Annapolis Junction, MD, offering a $190K–$210K compensation and Active TS/SCI w/ Polygraph clearance. You will support secure enclave development networks, conduct testing, maintain SOPs, manage accounts, and ensure baseline security in a collaborative, small-team environment.

Required: technical degree and 15+ years or equivalent. Expertise in Windows Server, AD, Group Policy, Linux, NetApp, and VMware stacks.