Systems Administrator SME Security Clearance

Title: Systems Administrator SME
Location: Herndon, VA

Active TS/SCI w/ Polygraph needed to apply

Cornerstone Defense is the Employer of Choice within the Intelligence, Defense, and Space communities of the U.S. Government. Realizing early on that our most prized assets are our employees, we continually focus our attention on improving the overall work/life experience they have supporting the mission. Our Team is pushed every day to use their industry leading knowledge to provide end-to-end solutions to combat our nation's toughest and most secure problems.

If you are looking for a place to not only be professionally challenged, but encouraged and supported by a company that cares, don't look any further than Cornerstone Defense.

• 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
• College America 529
• Fitness Reimbursement Program
• Travel Assistance
• Norton Lifelock Benefit Solutions
• Life Planning Financial & Legal Services

We are actively seeking candidates with a minimum of 16 years experience, and a range of skill levels from basic to advanced. Bachelors or Masters Degree are preferred in one or more of the disciplines described below where specific skills may include the following:

• Systems Administration
  • Provide Tier I & II support for enterprise systems and elevate advanced issues as needed.
  • Troubleshoot server, operating system, application, and connectivity issues.
  • Support daily operations, monitoring, maintenance, and upgrades for on-prem, virtual, and cloud systems.
  • Document incidents, problems, and service requests using Service Now.
  • Support asset management, inventory, and user onboarding activities.
  • Maintain system documentation, SOPs, and operational guides.
  • Deliver hardware within the WMA; limited travel required.
  • Provide guidance and knowledge transfer to junior team members.
• Quality Assurance & Testing
  • Test and validate system builds, patches, and configuration changes across Dev/Test/Prod environments.
  • Conduct functional, integration, regression, and post-deployment tests.
  • Develop test documentation including Test Plans, Test Cases, Defect Logs, and Test Reports.
  • Identify, log, and track defects through closure.
  • Create test scenarios that include both expected outcomes and failure conditions.
  • Perform smoke testing and pre/post-deployment validation for production releases.
  • Identify risks or gaps early in development.
  • Recommend areas for automated testing improvements.
• Cloud & Dev Ops Support
  • Validate deployments in AWS, Azure, and hybrid cloud environments.
  • Verify IAM roles, access controls, and Zero Trust security configurations (ACLs, security groups, routing rules, firewall settings).
  • Validate DNS paths, connectivity, and system availability after updates or builds.
  • Confirm server build integrity through post-deployment checks (connectivity, logs, performance).
  • Ensure systems remain available after certificate updates and patching.

• Strong proficiency with:
  • Windows Server
  • Active Directory
  • AWS and/or Azure
  • Virtualized infrastructure
  • Service Now or similar ITSM tools
• Ability to work effectively within Agile teams including Developers, Technical Managers, Business Analysts, and Product Owners.
• Strong analytical ability, communication skills, and problem-solving capabilities.
• Ability to work independently and collaboratively.
• Experience mentoring or providing technical knowledge transfer.