Linux Administrator

ATR International; San Jose (CA); Hybrid; USD 120,000 - 150,000; Full time

Job summary

ATR International seeks a Linux Systems Administrator with a strong cybersecurity compliance background for hybrid work in San Jose, CA. The role focuses on securing Linux infrastructure and ensuring compliance with NIST 800-171, CMMC, DFARS, and ITAR-related controls.

You will harden systems, manage patches, and support audits while collaborating with IT security, engineering, and program teams to meet export control and data handling requirements.

Qualifications

• 3–5+ years of Linux system administration experience.
• Experience with cybersecurity compliance frameworks (NIST 800-171, CMMC, RMF, or similar).
• Experience in aerospace, defense, or ITAR-regulated environments.
• Familiarity with STIG/CIS hardening practices.
• Scripting in Bash or Python for automation.
• Strong understanding of network security fundamentals.
• Experience with Linux installation and deployment.

Responsibilities

• Administer, maintain, and troubleshoot Linux servers.
• Configure network interfaces and firewall rules across distros.
• Implement system hardening standards (CIS Benchmarks, STIGs).
• Support compliance audits for NIST 800-171, CMMC, DFARS.
• Monitor, patch, remediate, and manage POA&Ms.
• Collaborate with IT security, engineering, and program teams on export control and data handling.
• Maintain documentation of configurations, security controls, and audit evidence.
• Support incident response and security monitoring.
• Manage user access controls, LDAP and SMB/Samba, logging, and backups.

Skills

Linux system administration

Cybersecurity compliance

Bash/Python scripting

Network security fundamentals

System hardening

Education

Bachelor's degree in CS/InfoSec or equivalent

Tools

Ansible

Puppet

RHCSA/RHCE certification

Job description

Hybrid in San Jose, CA (onsite as needed, 1-3 days a week)

We are seeking a Linux Systems Administrator with a strong background in cybersecurity compliance within the aerospace or defense industry. This role will be responsible for maintaining, securing, and hardening Linux-based infrastructure while ensuring compliance with relevant federal and industry security frameworks (e.g., NIST 800-171, CMMC, DFARS, ITAR-related IT controls).

Key Responsibilities

• Administer, maintain, and troubleshoot Linux servers (RHEL/CentOS/Ubuntu, etc. — specify distros used internally)
• Configure static and dynamic (DHCP) network interfaces on Linux distributions using to Implement iptables, nftables, or firewalld rules to control, allow, or block traffic between subnets and secure node boundaries.ols like iproute2, Netplan, or NetworkManager.
• Implement iptables, nftables, or firewalld rules to control, allow, or block traffic between subnets and secure node boundaries.
• Implement and maintain system hardening standards (CIS Benchmarks, STIGs)
• Support compliance audits and assessments related to NIST 800-171, CMMC, DFARS, or similar frameworks
• Monitor systems for vulnerabilities; manage patching, remediation, and POA&Ms
• Collaborate with IT security, engineering, and program teams to ensure systems meet export control and data handling requirements
• Maintain documentation for system configurations, security controls, and audit evidence
• Support incident response and security monitoring activities
• Manage user access controls, with LDAP and SMB/Samba configuration, logging, and system backups

Required Qualifications

• 3–5+ years of Linux system administration experience (specify years based on level)
• Demonstrated experience with cybersecurity compliance frameworks (NIST 800-171, CMMC, RMF, or similar)
• Experience in aerospace, defense, or other ITAR-regulated environments
• Familiarity with STIG/CIS hardening practices
• Scripting experience (Bash, Python, or similar) for automation
• Strong understanding of network security fundamentals
• Experience with Linux installation and application deployment.

Preferred Qualifications

• Relevant certifications (e.g., RHCSA/RHCE, Security+, CISSP, CAP)
• Experience supporting CMMC Level 2 or 3 compliance efforts
• Experience with configuration management tools (Ansible, Puppet, etc.)
• Familiarity with export control (ITAR/EAR) requirements as they relate to IT systems
• Experience with Linux installation and application deployment on PowerPC.

Education

• Bachelor's degree in Computer Science, Information Security, or related field, or equivalent experience