Principal Engineer - Systems (Unix Systems Administrator) - CO - Boulder, United States

Originally posted 7 October 2026 by the employer.

About the role

This role involves engineering, securing, and maintaining business-critical Linux and FreeBSD infrastructure on bare-metal hardware and virtualized platforms. You will serve as a primary technical authority on system architecture and security compliance, ensuring environments meet stringent federal and defense-industry standards.

What you'll do

• Design, deploy, and maintain enterprise Linux and/or FreeBSD environments on-premises and within cloud infrastructure.
• Implement deep system hardening and mandatory access controls using SELinux by writing custom policies.
• Apply, automate, and maintain strict security baselines according to DISA STIGs and CIS Benchmarks.
• Architect and manage secure enclaves compliant with Cybersecurity Maturity Model Certification (CMMC) standards.
• Deploy, secure, and manage virtualized environments and containerized workloads.
• Automate patching, configuration management, and compliance auditing utilizing in-house and industry automated tools (e.g., Ansible).
• Troubleshoot complex OS, network, and storage issues at the kernel and hypervisor levels.

What you'll need

• 10+ years of hands-on, enterprise-level system administration experience specifically with Linux and/or FreeBSD operating systems.
• Bachelor’s degree in Computer Science, Information Technology, Cybersecurity, or a related technical field.
• Must be a U.S. Citizen with the ability to obtain and maintain a TS/SCI U.S. Government Security Clearance.
• Proven track record of hardening systems using DISA STIGs and CIS Benchmarks, practical knowledge of SELinux configuration.
• Strong working knowledge of CMMC frameworks and the specific technical guardrails required for handling CUI.
• Demonstrated ability to provision, manage, and secure operating systems on bare-metal hardware and within scalable cloud environments.
• Solid foundational knowledge of virtualization technologies and containerization runtimes.

Nice to have

• Red Hat Certified Engineer/Administrator (RHCE/RHCSA), Linux Foundation Certified Engineer/Administrator (LFCE/LFCS), CompTIA Linux+, or BSD Certification Group (BSDA/BSDP) certifications.
• Certified Information Systems Security Professional (CISSP), CompTIA Advanced Security Practitioner (CASP+), or CompTIA Security+ certifications.
• AWS Certified SysOps Administrator/Security Specialty, or Certified Kubernetes Administrator (CKA) certifications.

Skills: Linux, FreeBSD, SELinux, DISA STIGs, CMMC, virtualization, containerization