Senior Principal Linux/Windows System Administrator

MTSI is seeking a highly skilled Senior Linux/Windows System Administrator with extensive experience in integrating Red Hat Enterprise Linux (RHEL) systems into Microsoft Active Directory domains within a secure, enterprise environment. The ideal candidate will have a strong background in Linux and Windows administration, security hardening, and cross-platform integration, ensuring compliance with organizational and regulatory standards.

Responsibilities

• Administer and maintain Red Hat Enterprise Linux & Windows servers and workstations in a mission-critical environment.
• Work with the Security and IT teams to develop and implement a plan to deploy RHEL workstations and servers within the CMMC framework for use in our enterprise environment.
• Administer and maintain Microsoft Azure and Office 365 services.
• Manage all aspects of Windows Active Directory infrastructure including Domain Controllers, DNS servers, DHCP servers, and file servers.
• Configure and manage HPC (High Performance Computing) Linux clusters.
• Installation, configuration, and support of servers, enterprise storage and associated equipment, network and direct attached storage systems and associated equipment.
• Integrate Linux systems with Microsoft Active Directory for authentication and policy management.
• Implement and maintain security best practices, including system hardening, patch management, and compliance with security frameworks (e.g., DISA STIGs, CMMC, CIS benchmarks).
• Troubleshoot and resolve complex issues related to Linux and Windows interoperability.
• Automate administrative tasks using scripting languages (e.g., Bash, Python, Ansible).
• Collaborate with security teams to ensure systems meet cybersecurity requirements.
• Track and maintain computer assets using asset management tools and ensure asset management systems have up-to-date information.
• Monitor system performance and implement proactive measures for optimization and reliability.
• Provide analysis related to the design, development, and implementation of hardware and software solutions.
• Document system deployments and configurations.
• Research and/or contact vendors regarding technical problems and solutions.
• Demonstrate professionalism in response to customer requests.
  
  

Required Qualifications

• 14 years of total System Administration experience
• 7 years of experience in Linux system administration
• 5 years managing Red Hat Enterprise Linux in Microsoft Windows/ Azure enterprise environments.
• Proven experience integrating Linux systems with Microsoft Active Directory (SSSD, Kerberos, LDAP, Intune).
• Strong knowledge of security hardening and compliance standards.
• Proficiency in shell scripting and automation tools (Ansible preferred).
• Familiarity with virtualization and cloud technologies (Azure preferred).
• Excellent troubleshooting and problem-solving skills.
  
  

Required Education

• BS or equivalent degree in Computer Science or related field.
  
  

Preferred Qualifications

• Red Hat Certified Engineer (RHCE) or equivalent certification.
• Windows Server Hybrid Administrator Associate or similar Microsoft 365 certifications.
• Experience in DoD or other regulated environments with strict security requirements.
• Knowledge of SELinux, firewalld, fapolicyd, and secure networking practices.
• Experience managing GCC High Microsoft Azure/ Office 365.
• Experience configuring & managing Bright High Performance Computing clusters.
  
  

Required Clearance

• Must have the ability to obtain/maintain a US government security clearance.
• US citizenship is required.