Senior System Administrator

SITEC is seeking a Senior Systems Administrator to support lifecycle sustainment activities for commercial and custom-developed education, learning, and training applications. This role will join an existing technical team responsible for maintaining secure, reliable, and high-performing IT systems across hybrid on-premises and cloud-based environments. The ideal candidate is a self-motivated Systems Administrator with strong Windows and Linux experience, hands‑on patching and vulnerability remediation knowledge, and the ability to support mission‑critical systems in a fast‑paced DoD environment. Responsibilities The Senior Systems Administrator will provide operational support, maintenance, troubleshooting, patching, automation, and system administration across enterprise Windows, Linux, and cloud-hosted environments. This position will support system reliability, security compliance, infrastructure modernization, and lifecycle sustainment activities. Administer and maintain Windows Server and Linux server environments. Perform IAVA patching, vulnerability remediation, and compliance reporting across enterprise systems. Provide troubleshooting, maintenance, and operational support for on-premises and cloud-hosted IT environments. Execute system patching, software maintenance, upgrades, hardening, and disk management. Implement and manage Windows Group Policy Objects and Active Directory-related administration. Develop automation scripts using PowerShell, Bash, Python, or related scripting languages. Support AWS cloud infrastructure using services such as EC2, Lambda, CloudFormation, and IAM. Assist with infrastructure as code initiatives using Ansible and Terraform. Develop and maintain system automation tools to improve reliability, efficiency, and uptime. Work collaboratively with technical teams in a fast‑paced, mission-focused environment. Required Qualifications Active TS/SCI with Polygraph. 15 years of Systems Administration experience supporting programs of similar scope, type, and complexity. Bachelor's degree in a technical discipline; 5 additional years of SA experience may be substituted in lieu of a degree. DoD 8570 compliance with IAT Level I. Experience maintaining Windows Server environments, including hardening, patching, upgrades, and disk management. Experience administering Linux servers, including patching and software maintenance. Experience with IAVA patching and reporting. Experience maintaining and upgrading installed software across enterprise systems. Strong troubleshooting and problem-solving skills across computer systems and software. Desired Skills Strong hybrid Linux/Windows Systems Administration background. Hands‑on experience with AWS services such as EC2, Lambda, CloudFormation, and IAM. Experience with automation and scripting tools including Ansible, Terraform, PowerShell, Bash, and Python. Experience with Active Directory and Group Policy Management. Understanding of cloud security practices, patch management, and compliance reporting. Ability to work independently and collaboratively in a fast‑paced technical environment. About SITEC SITEC is an employee- and customer-focused Information Technology and Professional Services firm specializing in cybersecurity, software and systems engineering, systems administration, and lifecycle support services. We design, develop, and deliver mission-focused technology solutions that support the continuous operation and modernization of critical customer platforms. #J-18808-Ljbffr