Senior Systems Engineer - Linux/Windows Security

L3Harris; Waco (TX); On-site; USD 110,000 - 160,000; Full time

Job summary

L3Harris Technologies is seeking an Information Security Systems Engineer to administer secure Linux and Windows environments in a defense-focused lab, ensuring patching, IAM, and hardening across air-gap networks.

Role requires DoD Secret clearance, experience with STIGs, AD/LDAP, and automation tools. You’ll build resilient infrastructure, support secure development platforms, and aid accreditation efforts from Waco, TX on a 9/80 schedule with on-site presence.

Qualifications

• Bachelor’s degree in CS/IT or related field with required experience, or 13+ years experience in lieu of degree.
• Hands-on Linux on Red Hat-based distributions, Windows administration, AD, scripting, network and storage services, hardening, and secure environments.
• DoD Active Secret Clearance required.
• Experience with configuration management/automation tools: Ansible/AWX, Puppet, Chef; authentication tech: AD/FreeIPA/LDAP/Kerberos/IDM; and code platforms: GitLab/GitHub/SVN.
• Security+ or equivalent certification strongly desired; STIG implementation and audit readiness valued.
• Familiarity with CI/CD, DevOps, logging/monitoring, virtualization, multi-OS, cloud, and security troubleshooting in distributed systems.

Responsibilities

• Administer Red Hat Linux, Windows Server/workstations, provisioning, patching, privilege management, IAM, config changes, lifecycle support in secure lab and isolated networks.
• Build and maintain DNS, DHCP, NFS, automounts, SMB/Samba, Windows domain services, Active Directory, LDAP, NTP, virtualization, storage, backup, and monitoring; document and ensure recoverability in air-gap environments.
• Support engineers with secure development infra, remote access, standard images, DevOps platforms, source-code management, and multi-OS troubleshooting with clear ownership.
• Partner with security stakeholders to harden/audit systems; implement STIG baselines, patching, vulnerability remediation, endpoint protection, logging, and evidence for CMMC, ATO, continuous monitoring and accreditation.
• Maintain inventories, ownership, diagrams, SOPs, change records, audit artifacts, and reporting of gaps and actions.
• Provide on-site incident response, outages, recovery, vendor coordination, and stabilize a local secure-area support model toward accreditation sustainment.

Skills

Linux admin

Windows admin

Active Directory

Shell scripting

System hardening

Ansible

AWX

Puppet

Chef

GitLab

Education

Bachelor's Degree in CS/IT

Graduate Degree in CS/IT

13+ years experience in lieu of degree

Tools

FreeIPA

LDAP

Kerberos

GitHub

GitLab

SVN

AD/LDAP authentication

Job description

L3Harris Technologies is seeking an Information Security Systems Engineer to administer secure Linux and Windows environments in a defense-focused lab, ensuring patching, IAM, and hardening across air-gap networks.

Role requires DoD Secret clearance, experience with STIGs, AD/LDAP, and automation tools. You’ll build resilient infrastructure, support secure development platforms, and aid accreditation efforts from Waco, TX on a 9/80 schedule with on-site presence.