Senior Linux System Administrator/System Engineer with Security Clearance

Cornerstone Defense; Annapolis (MD); On-site; USD 179,000 - 242,000; Full time

Benefits offered by this job

Medical, Dental and Vision Plans

Generous PTO

401(k)

HSA and FSA options

Life and Disability Insurance

Tuition Reimbursement

Travel Assistance

Perks at Work Discount Program

Job summary

Cornerstone Defense is seeking a Senior Linux System Administrator/System Engineer to support a high-visibility mission environment. You will administer Linux systems (CentOS/RHEL), manage JBoss/Wildfly middleware, and virtualized infrastructure, emphasizing security and availability. Strong independent work ethic and collaboration across teams are required.

Requires Active TS/SCI w/ Polygraph. Expect exposure to storage, networking, and scripting, plus opportunity for advanced training and

Qualifications

• 10+ years of Linux System Administration/Engineering in mission environments.
• Extensive experience with CentOS/RHEL, JBoss/Wildfly, and Oracle DB design/migration.
• Strong scripting (Shell, Python) and automation skills; security-focused.

Responsibilities

• Provide expert-level administration, engineering, and sustainment of Linux-based systems.
• Collaborate across mission teams to ensure reliability, availability, and compliance.
• Implement storage, networking, security, and automation as part of infrastrucutre maintenance.

Skills

Linux admin

JBoss/Wildfly

Scripting

Security+ certification

Ansible

Education

CompTIA Security+ certification

Tools

VMware

JBoss/Wildfly

LDAP/Kerberos

Job description

Title: Senior Linux System Administrator/System Engineer Location: Annapolis Junction Compensation Range: $190

• 210k
• Clearance:
• Active TS/SCI w/ Polygraph needed to apply
• Company Overview: 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.
• Benefits Overview: Cornerstone Defense offers a very comprehensive benefits package including, but not limited to: 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 Services
• Description: The Sr. System Administrator / System Engineer supports a high-visibility, mission‑critical environment by providing expert‑level administration, engineering, and sustainment of Linux‑based systems across secure facilities. This role requires deep technical proficiency in CentOS/RHEL environments, enterprise middleware (JBoss/Wildfly), virtualization, automation, and secure system operations. The engineer will collaborate across mission teams, and provide support to maintain system reliability, availability, and compliance. The position demands a strong independent work ethic, adaptability, and broad familiarity with modern infrastructure components including storage, networking, security, and scripting. Required Skills:
• 10 + years' experience administering to, and engineering solutions with Oracle's database. Extensive experience with database design and modeling; as well as the collection and interpretation of customer requirements relevant to database migration, troubleshooting, performance observation and tuning.
• Minimum 10 years of experience as a Linux System Administrator or Systems Engineer supporting mission environments.
• Extensive hands‑on experience with:
• CentOS / RHEL administration
• Installation, configuration, and sustainment of JBoss/Wildfly
• VMware VM creation, configuration, and operations
• Strong ability to work independently in fast‑paced, mission‑oriented environments.
• CompTIA Security+ certification required Desired Skills:
• Experience with Red Hat Ansible for automation and configuration management.
• Storage administration
• Networking fundamentals
• Security compliance and hardening
• Authentication systems (e.g., LDAP, Kerberos)
• Scripting (Shell, Python preferred)
• Physical server administration Additional Desired Skills or Familiarization:
• Oracle Database or related DBA experience
• Working with JavaScript Object Notation (JSON)