**ManTech** seeks a motivated, career and customer-oriented **Senior Systems Administrator** to join our team in **Doral, FL** **.** **Responsibilities include but are not limited to:** + Leads the maintenance, configuration, and reliable operation of complex IT infrastructure, including servers, networks, and virtualization technologies, particularly in critical or high-security environments. + Possesses advanced expertise in operating systems, server hardware, virtualization platforms, network infrastructure, and cybersecurity best practices. + Installs, configures, and upgrades intricate systems and software, optimizing performance, security, and availability. + Diagnoses and resolves complex hardware and software issues using advanced troubleshooting tools and techniques. + Develops and maintains comprehensive system documentation, including configuration guides, troubleshooting procedures, and Disaster Recovery Plans. + Drives the implementation of automation processes to enhance IT operational efficiency and contributes to strategic infrastructure projects. + Provides leadership, direction, and mentorship to subordinate Systems Administrators, fostering team growth and technical proficiency. **Minimum Qualifications:** + BA/BS in field necessary to assume Senior Systems Administrator duties or 4 years of additional experience in lieu of a degree. + 9+ years of experience with 5+ years of relevant Systems Administrator III experience. + Proven expertise in managing and maintaining complex IT infrastructure, including operating systems (Windows Server, Linux), server hardware, and network components. + Advanced proficiency in virtualization technologies (e.g., VMware, Hyper-V) and strong skills in scripting and automation (e.g., PowerShell, Bash). + Deep understanding of system security best practices, hardening techniques, and comprehensive troubleshooting methodologies for hardware and software. + Familiarity with IT Service Management (ITSM) principles and practices. + Exceptional analytical and problem-solving abilities, with a track record of identifying root causes and implementing effective solutions for complex technical issues. + Ability to obtain DoD 8570.01-M IAT Level II certification within six months of starting work on the Task Order. **Desired Qualifications:** + Master’s degree in Computer Science, Information Technology, or a related field. Experience with cloud computing platforms (e.g., AWS, Azure, GCP). + Knowledge of containerization technologies (e.g., Docker, Kubernetes). + Familiarity with DevOps practices and tools. Experience with monitoring and performance tuning of systems. + Relevant certifications in systems administration (e.g., Microsoft Certified Solutions Expert (MCSE), Red Hat Certified Systems Administrator (RHCSA), CompTIA Server+). + Experience at a DoD Combatant Command (e.g., SOUTHCOM, NORTHCOM, CENTCOM, CYBERCOM, INDOPACOM, EUCOM, AFRICOM, STRATCOM, TRANSCOM, SOCOM, SPACECOM) or a component is desired. **Clearance Requirements:** + Must have an active Secret clearance **Physical Requirements:** + Must be able to remain in a stationary position 50% + Constantly operates a computer and other office productivity machinery, such as a calculator, copy machine and computer printer + The person in this position frequently communicates with co-workers, management and customers, which may involve delivering presentations. Must be able to exchange accurate information in these situations. ManTech International Corporation, as well as its subsidiaries proactively fulfills its role as an equal opportunity employer. We do not discriminate against any employee or applicant for employment. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, or status as a protected veteran. If you are a qualified individual with a disability and require a reasonable accommodation to apply for a position with ManTech through its online applicant system, please email us at careers@mantech.com and provide your name and contact information.