Senior Linux System Administrator/System Engineer with Security Clearance

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

Benefits offered by this job

Medical, Dental & Vision

Generous PTO

401(k)

HSA/FSA options

Life & Disability Insurance

Tuition Reimbursement

Referral Program

Leads Generation Program

Job summary

Cornerstone Defense LLC seeks a Senior Linux System Administrator/System Engineer to support a high-visibility, mission-critical Linux environment across secure facilities. The role emphasizes CentOS/RHEL administration, middleware sustainment (JBoss/WildFly), virtualization, automation, and strict security compliance.

Independent work ethic and adaptability are essential. Required 10+ years in Linux system administration or systems engineering, with hands-on experience in virtualization and

Qualifications

• 10+ years of Linux System Administration experience in mission environments.
• Extensive hands-on CentOS/RHEL administration with JBoss/WildFly.
• VMware VM creation, configuration, and operations.
• CompTIA Security+ certification required.
• Strong scripting and automation experience.
• Storage and networking fundamentals for secure systems.

Responsibilities

• Provide expert Linux system administration and engineering in mission-critical environments.
• Sustainment and integration of JBoss/WildFly middleware and virtualization.
• Collaborate across mission teams to maintain system reliability and compliance.
• Implement security hardening and incident response readiness.

Skills

Linux System Admin

JBoss/WildFly

Scripting (Shell/Python)

Automation (Ansible)

Security & hardening

Networking basics

LDAP/Kerberos

Oracle DBA

Independent work

Tools

VMware

JBoss/WildFly

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)