SELinux MLS System Admin (Mandatory - TS/SCI with CI Poly)

Company Overview

At 4A Consulting, we turn complexity into opportunity. Founded in 2014 and headquartered in Baltimore, MD, we are a women-owned, boutique consulting firm specializing in delivering innovative, data-driven solutions to both the Federal Government and Fortune 500 clients. Our team blends deep industry knowledge with advanced technologies to design tailored strategies that drive measurable and sustainable outcomes. We pride ourselves on an agile, collaborative approach that helps organizations navigate challenges and seize emerging opportunities in a rapidly evolving digital landscape. At 4A, we don’t just deliver projects, we build trusted partnerships that empower our clients to lead with confidence in the digital age.

Position Overview

We are seeking a highly experienced SE Linux–based MLS Systems Administrator Subject Matter Expert (SME) to support secure, enterprise-grade High Performance Computing (HPC) environments. This role focuses on designing, deploying, automating, and maintaining Mandatory Access Control (MAC) configurations across large-scale Linux systems. The ideal candidate brings deep expertise in SE Linux, kernel-level troubleshooting, automation, and identity management within highly secure environments.

Key Responsibilities

• Design, develop, configure, and maintain integrated Red Hat Enterprise Linux (RHEL) and SE Linux MLS configurations across systems, networks, and storage
• Implement and manage Mandatory Access Control (MAC) policies, security contexts, labeling, and least-privilege access models
• Collaborate with DevSecOps automation teams to deploy SE Linux MLS configurations using site-specific inputs
• Troubleshoot and resolve SE Linux policy, kernel, and system-level issues
• Debug Linux kernel issues using source code review, system logs, and tools such as crash and systemtap
• Manage Satellite repositories to apply patches and build custom kernels addressing functional and security requirements
• Automate configuration, patching, and maintenance activities using Ansible and Satellite Server
• Ensure identity and access integrations using LDAP and token-based authentication systems
• Coordinate with security teams to ensure RMF, RTB, and related security controls are met and documented
• Ensure high-speed networking and InfiniBand fabrics operate correctly with MAC labeling and MLS controls
• Maintain system performance while enforcing MLS and security requirements
• Modify existing scripts or software to correct errors and improve performance
• Provide technical support to staff and end users for deployed configurations
• Apply best practices in software engineering, documentation, and secure system design
  
  

Required Qualifications

• Bachelor’s degree in Computer Science, Information Systems, or related discipline
• 10 years of professional experience in Linux systems administration or system software development
• Minimum 5 years of experience developing or supporting system software in heterogeneous, multi-platform environments
• Expert-level proficiency in SE Linux configuration, including policy development, MAC labeling, security contexts, MLS FreeIPA, and MLS networking
• Strong proficiency in Bourne/Bash and Expect scripting
• Experience debugging Linux kernel issues using source code analysis, system logs, crash, and systemtap
• Experience managing Satellite repositories, patching systems, and building custom kernels
• Experience automating system configuration and maintenance using Ansible and Satellite Server
• Understanding of identity management systems including LDAP and token-based authentication
• Active TS/SCI with CI Poly clearance required
  
  

Preferred Qualifications

• Experience working in High Performance Computing (HPC) environments
• Experience with high-speed fabrics such as InfiniBand or Omni-Path, including subnet management and fabric monitoring
• Experience with file systems such as Lustre, NFS, or other direct-attached storage solutions
• Knowledge of Ethernet networking and RDMA communications
• Experience with scripting languages such as Python, Perl, Korn
• Experience using revision control systems such as CVS, SVN, or Git
• Strong organizational skills with the ability to prioritize and multitask
• Excellent written and verbal communication skills
• Proven ability to analyze, debug, and maintain large scripting and automation codebases
  
  

Why Join 4A

• Be part of a mission-driven, women-owned consulting firm with a reputation for excellence.
• Work on high-impact projects across federal and commercial clients.
• Collaborate in an inclusive, growth-oriented culture where innovation is valued.
• Access career development programs, mentorship, and learning opportunities.
• Enjoy a comprehensive benefits package, flexible work options, and a focus on work-life balance.
  
  

Equal Opportunity Statement

4A Consulting is an Equal Opportunity Employer. We celebrate diversity and are committed to creating an inclusive environment for all employees. All employment decisions are made without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability status, protected veteran status, or any other characteristic protected by law.