Senior Systems Administrator

General Information

Requisition # R64751 Locations USA-VA-Chantilly Posting Date 12/12/2025 Security Clearance Required TS/SCI w/ Poly Remote Type Onsite Time Type Full time

Description & Requirements

Unlock the secrets of intelligence with MANTECH! Join a dynamic team at the forefront of national security, providing advanced solutions to government intelligence agencies. Since 1968, we’ve been solving the toughest challenges with groundbreaking tech. Explore thrilling projects in Digital Transformation, Cybersecurity, IT, Data Analytics and Software Development. Elevate your career and make a difference. Your adventure begins now—unleash your potential with MANTECH!

MANTECH seeks a motivated and skilled Senior Systems Administrator to join our sustainment team in Chantilly, VA. In this role, you will support a mission-critical enterprise environment by ensuring the continued health, performance, and compliance of complex network and system infrastructures. You will help drive key Operations and Maintenance (O&M) activities while leveraging strong technical expertise and collaborative problem-solving to maintain optimal system functionality.
 

Responsibilities include, but are not limited to:

• Provide hands-on O&M support for enterprise systems, including break-fix resolution and routine sustainment tasks
• Monitor system performance, health, and availability using enterprise tools such as ServiceNow and JIRA
• Collaborate with engineering and Assessment & Authorization (A&A) teams to apply patches, perform upgrades, and ensure RMF compliance
• Support Identity and Access Management (IdAM) initiatives, including PKI, LDAP, and related authentication technologies
• Maintain system documentation, configuration management, and security baselines in tools such as GitLab and Confluence
• Conduct vulnerability scans, apply security patches, and ensure adherence to established cybersecurity standards
• Contribute to DevOps and Agile processes by supporting deployments and collaborating closely with QA and development teams
• Provide clear and timely communication on system status, planned maintenance, and incident response activities to stakeholders 

Minimum Qualifications:

• Bachelor’s degree or 4+ additional years of relevant experience in lieu of a degree
• 5+ years of experience in IT, O&M, sustainment, and/or break-fix support
• Demonstrated experience performing system break-fix and troubleshooting activities
• Experience supporting cloud and virtualized environments
• Proficiency with PKI and IdAM COTS/custom solutions
• Familiarity with Agile and DevOps methodologies
• IAT Level II certification (GSEC, Security+, SSCP, or CCNA-Security) 

Preferred Qualifications:

• Experience with automation platforms such as Puppet and Ansible
• Knowledge of high-availability and clustered system architectures
• Familiarity with IdAM technologies including PKI, LDAP, SAML, OAuth 2.0, OpenID Connect, and API Gateways
• Proven experience collaborating within DevOps and Agile engineering teams
• Proficiency using ticketing systems such as ServiceNow and JIRA
• Understanding of network and cloud infrastructure technologies
• Strong knowledge of patch management systems and group policy configuration 

Clearance Requirements:

• Active TS/SCI with CI Polygraph is required for this position 

Physical Requirements:

• Must be able to remain in a stationary position up to 50% of the time
• Needs to occasionally move about inside the office to access file cabinets, office machinery, etc.
• 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 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 careers@mantech.com and provide your name and contact information.