Position Overview

We are seeking a Senior Systems Administrator (SELinux / MLS SME) to support a mission-critical enterprise Multi-Level Security (MLS) configuration team. This role supports highly secure computing environments, including the Centralized SuperComputing Facility (CSCF) and other classified programs.

In this position, you will serve as a Linux security expert, specializing in SELinux and MLS configurations within large-scale enterprise and high-performance computing environments. You will help design, implement, and troubleshoot secure Linux systems while supporting advanced computing environments and mission-critical infrastructure.

This is a highly technical role for a Linux security specialist who enjoys solving complex system challenges and working in advanced secure environments.

Locations: Littleton, CO • King of Prussia / Valley Forge, PA • Herndon, VA • Springfield, VA

Key Responsibilities

• Serve as a Subject Matter Expert (SME) for SELinux and Multi-Level Security (MLS) configurations across enterprise Linux environments

• Support secure Linux environments for enterprise systems and High Performance Computing (HPC) infrastructure

• Configure and maintain SELinux policies, security contexts, MAC labeling, and least-access policies

• Troubleshoot and debug SELinux policy and kernel-level issues using system logs and debugging tools

• Develop and maintain secure MLS configurations, including MLS FreeIPA and secure networking configurations

• Write and maintain automation and operational scripts using Bourne/Bash and Expect

• Manage Linux patching and repository management using Satellite Server

• Build and maintain custom Linux kernels to meet functionality and security requirements

• Implement automation for configuration and patching using Ansible and Satellite Server

• Support and maintain identity and access management systems, including LDAP and token-based authentication

• Collaborate with engineering and infrastructure teams to ensure systems remain secure, compliant, and highly available

Required Qualifications

• Active TS/SCI with CI Polygraph (required to start)

• Bachelor's degree in Computer Science, Information Systems, or related field

• 10+ years of experience in Linux systems administration or related technical roles

• At least 5 years of experience working in heterogeneous, multi-platform computing environments

• Deep expertise with SELinux configuration and Multi-Level Security (MLS) environments

• Experience with:

  • SELinux policies and policy debugging

  • Mandatory Access Control (MAC) labeling

  • Security contexts

  • Developing least-access policies

  • MLS FreeIPA configurations

  • MLS Ethernet interface networking

• Proficiency in Bourne/Bash and Expect scripting

• Experience debugging Linux kernel issues, including analyzing system logs and source code

• Experience using Linux debugging tools such as crash and systemtap

• Experience managing Satellite repositories for patching and kernel management

• Familiarity with Ansible and Satellite Server for configuration and patch automation

• Experience working with identity management systems, including LDAP and token-based authentication

Preferred Qualifications

• Experience supporting High Performance Computing (HPC) environments

• Experience supporting enterprise MLS or cross-domain solutions

• Familiarity with large-scale Linux infrastructure in classified environments

• Experience improving automation, security, and system reliability across enterprise platforms