Jobs and Careers

Junior System Administration/ISSE

United Statesfull_timeVerifiedPosted 18 Feb 2026

About the role

Overview: Cyber Defense Technologies (CDT) is currently seeking a skilled System Administrator/ISSE to support, secure, and maintain Linux-based systems in a mission-critical environment. This role blends hands-on system administration with security engineering responsibilities, ensuring systems are reliable, compliant, and resilient against threats. This position will be onsite in Chantilly, VA.

Clearance Requirements: An active Top Secret/SCI with Full Scope Polygraph clearance is required. Applicants who do not meet these requirements will not be considered.

Responsibilities:

Administer, maintain, and troubleshoot Linux systems (e.g., RHEL, Rocky, Ubuntu)
Install, configure, and manage servers, services, and applications
Perform system monitoring, performance tuning, and capacity planning
Manage user accounts, permissions, and access controls
Apply patches, updates, and system hardening best practices
Support backup, recovery, and disaster recovery operations
Create and maintain system documentation and SOPs
Implement and maintain security controls in accordance with organizational and regulatory requirements
Support system accreditation and compliance efforts (e.g., RMF, NIST 800-53, STIGs)
Conduct vulnerability assessments, remediation, and security hardening
Analyze system logs and security alerts; respond to incidents as needed
Collaborate with cybersecurity teams to assess risks and implement mitigations
Ensure secure configurations across operating systems and services

Required Qualifications:

2+ years of experience as a Linux System Administrator or similar role
Strong experience administering Linux systems in production environments
Working knowledge of system security principles and best practices
Experience with system hardening, patch management, and access control
Ability to troubleshoot complex system and security issues
Strong documentation and communication skill

Preferred Qualifications:

Experience as an ISSE or in a security-focused systems role
Familiarity with security frameworks (NIST, RMF, CIS, or equivalent)
Familiarity with DISA STIGs and compliance tools (e.g., SCAP, OpenSCAP)
Scripting experience (Bash, Python, Ansible, etc.)
Experience with virtualization or containers (VMware, KVM, Docker, Kubernetes)
Experience with monitoring and logging tools (Splunk, ELK, Prometheus, etc.)
Security certifications (Security+, CISSP, SSCP, Linux+), or working toward one

Why Join Cyber Defense Technologies?
At CDT, we offer a collaborative and inclusive work environment where your expertise can help shape the future of cybersecurity and engineering solutions.

Compensation and Benefits:

Competitive salary based on experience.
Comprehensive benefits package, including health, dental, and retirement plans.
Opportunities for professional development and career advancement.

CDT is committed to hiring and retaining a diverse workforce. We are an Equal Opportunity employer making decisions without regard to race, color, religion, creed, sex, sexual orientation, gender identity, marital status, national origin, age, veteran status, disability, or any other protected class.

Apply Now:
If you are a proactive System Administration/ ISSE and thrive in dynamic environments, we encourage you to apply and join the CDT team!