Senior Linux System Administrator/System Engineer

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

401(k)

HSA and FSA options

Tuition Reimbursement and Training

Referral Program

Job summary

Cornerstone Defense LLC is seeking a Senior Linux System Administrator/System Engineer to support a high-visibility mission environment in Annapolis Junction. You will lead admin, engineering, and sustainment of Linux-based systems, with emphasis on CentOS/RHEL, JBoss/Wildfly, virtualization, and automation to ensure reliability and security.

The role requires deep technical expertise, ability to work independently in fast-paced settings, and a TS/SCI clearance with polygraph.

Qualifications

• 10+ years in Linux system administration or systems engineering in mission environments.
• Deep CentOS/RHEL administration and JBoss/Wildfly deployment.
• VMware VM creation, configuration, and operations.
• CompTIA Security+ certification is required.

Responsibilities

• Provide expert-level administration, engineering, and sustainment of Linux-based systems across secure facilities.
• Collaborate across mission teams and ensure system reliability, availability, and compliance.
• Manage enterprise middleware, virtualization, and scripting for automation and hardening.

Skills

Oracle DBA

Linux admin

JBoss/Wildfly

VMware

Shell/Python scripting

CompTIA Security+

Ansible automation

Storage administration

Networking fundamentals

Security compliance

LDAP/Kerberos authentication

Tools

JBoss/Wildfly

VMware

Ansible

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 ofcustomer 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)