ManTech is seeking a motivated, mission- oriented **Senior System Administrator** in the Chantilly, VA area to provide unparalleled support to our customer. A qualified Principal Systems Administrator will support a secure Windows-based Information System and will assist and support the installation, operation, and maintenance of all current and future Information Systems. Duties and responsibilities involve the support and administration of Windows servers and Windows workstations in an Amazon cloud environment. Additional duties include ICD 503 accreditation tasks, system documentation, analyzing and troubleshooting system anomalies, and ensuring optimal Information System performance. **Responsibilities include, but are not limited to:** + Establish and maintain servers and workstations in an Amazon cloud environment. + Establish and maintain S3 environments. + Plan and implement activities in support of ICD 503 requirements. + Perform Windows system administrative support to include adding and removing users, performing backups, installing software, monitoring system activity, and assisting users on a daily basis. + Maintain knowledge of AWS (C2S) snapshots, backups, storage and managing the creation and deletion according to policy. + Maintain and troubleshoot customer Windows servers and workstations. + Perform technical modifications and configuration changes on virtual systems. + Possess knowledge of Microsoft Windows 2012 Server, Active Directory, and associated server and workstation hardware. + Possess working knowledge of data backups, and antivirus systems. + Create/maintain standard operating procedures and technical documentation on an as needed or as requested basis. **Basic Qualifications:** + Bachelor's Degree in IT or related field. + 5+ years of experience in System Administration with a proven track record in managing IT systems. + Experience with AWS services. + Proficiency in managing S3 storage and configuring networking and security settings such as security groups. + Basic understanding of identity access management principles. ​ + Have a minimum of a DoD 8570 IAT Level II. + Strong problem-solving skills with the ability to troubleshoot and resolve technical issues. + Excellent communication and teamwork skills to collaborate effectively with diverse teams. + Ability to work in a fast-paced environment and manage multiple tasks simultaneously. **Preferred Qualifications:** + Advanced AWS certification (e.g., AWS Certified Solutions Architect, AWS Certified SysOps Administrator). + Experience with automation tools and scripting languages (e.g., Python, Bash). + Knowledge of DevOps practices and tools (e.g., Jenkins, Terraform). + Familiarity with containerization technologies (e.g., Docker, Kubernetes). + Strong understanding of cloud security best practices. + Previous experience in a similar role within a government or defense contracting environment. **Security Clearance Requirements:** + Must obtain a current TS/SCI clearance with Polygraph 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.