Senior Systems Administrator

MANTECH seeks a motivated, career and customer-oriented Senior Systems Administrator to join our CASTLE-NET Program team. This is a remote position . Be a part of an agile team to provide innovative, customer focused, and cost‑effective integrated enterprise IT support services in support of the client’s vision of engineering solutions for the Nation’s toughest challenges. Responsibilities include but are not limited to: Managing and maintaining the IT infrastructure to ensure reliability, performance, and security across Windows, Linux, and VMware environments. Installing, configuring, and supporting servers and virtualized environments while working closely with developers and stakeholders to ensure compliance with best practices. Maintaining comprehensive documentation of system configurations and procedures while ensuring maximum system security and availability. Planning and leading major technology assignments and evaluating performance results to recommend changes affecting project growth. Functioning as a technical expert across multiple project assignments, providing world‑class IT services and responsive customer support. Working with all stakeholders to ensure complete and functional systems that meet all requirements and exceed end‑user expectations. Minimum Qualifications: High School Diploma/GED with 12+ years of experience, or a bachelor’s degree in IT or Computer Science with 8+ years of experience in systems administration. Comprehensive knowledge of relevant operating systems including Windows Server, Red Hat, and CentOS, as well as virtualization technologies like VMware vSphere. Proficiency in scripting languages such as PowerShell, Bash, or Python for automation and performance tuning. Experience with system monitoring, patch management, and implementing rigorous security remediations. Must hold and maintain an 8140 IAT Level II compliant certification (e.g., Security+ CE, SSCP) upon hire. Ability to maintain relevant technical certifications such as Microsoft Certified: Windows Server, RHCSA, or VMware Certified Professional (VCP). Preferred Qualifications: Certified Information Systems Security Professional (CISSP certification). Familiarity with the USACE IT environment, regulatory requirements, and data security best practices. Self‑starter with excellent people skills who can communicate effectively with technical and non‑technical stakeholders to drive change throughout an organization. Clearance Requirements: Must possess a Secret security clearance prior to starting this position. Physical Requirements: The person in this position must be able to remain in a stationary position 50% of the time. Occasionally move about inside the office to access file cabinets, office machinery, or to communicate with co‑workers, management, and customers, via email, phone, and or virtual communication, which may involve delivering presentations. MANTECH International Corporation considers all qualified applicants for employment without regard to disability or veteran status or any other status protected under any federal, state, or local law or regulation. If you need a reasonable accommodation to apply for a position with MANTECH, please email us at View email address on click.appcast.io and provide your name and contact information. #J-18808-Ljbffr