Senior System Administrator

Clearwaters.IT is seeking an experienced Senior System Administrator to support the coordination with business and technology teams, ascertaining system requirements, such as program functions, output requirements, input data acquisition, and system techniques and controls. The environment is dynamic, and client needs are often evolving; flexibility and forward-thinking views are important for success.  

This position is 100% onsite, located in Washington D.C. and is contingent upon the award of the contract. Candidates must have an Active TS security clearance with SCI eligibility. 

Responsibilities: 

• Lead the design, deployment, and management of enterprise server environments, including Windows Server, Linux, VMware vSphere/ESXi, and cloud platforms. 

• Implement and manage Active Directory, Microsoft Exchange, DNS, DHCP, Group Policy, and related services. 

• Plan, schedule, and perform system patches, firmware upgrades, and security hardening in accordance with DISA STIGs, CIS Benchmarks, and NIST 800-53 controls. 

• Conduct vulnerability assessments using tools such as Tenable.SC; remediate findings and document corrective actions. 

• Administer centralized storage solutions, including SAN/NAS environments and perform backup and recovery operations using enterprise backup tools. 

• Monitor system and network performance using enterprise monitoring platforms (e.g., SolarWinds); implement corrective actions to optimize uptime and availability. 

• Develop and maintain PowerShell and Bash scripts for system automation and configuration management. 

• Manage security controls and audit logs; perform system security audits and provide detailed reports. 

• Support virtualization environments, including hypervisor deployment, resource optimization, and high-availability configurations. 

• Lead incident response for critical system outages and security incidents; provide after-action reporting and mitigation strategies. 

• Maintain compliance with software licensing agreements and support internal and external audits. 

• Provide technical mentorship to junior administrators and collaborate with engineering teams on infrastructure projects.

• Bachelor’s degree in Computer Science, Information Technology, or a related field AND a minimum of eight (8) years of system administration experience or an additional six (6) years of relevant experience in lieu of a degree. 

• Must have an Active TS security clearance with SCI eligibility. 

• Must be a U.S. citizen. 

• Must possess one of the following certifications such as COMPTIA A+, Network+, and/or Security+ Information Technology Infrastructure Library (ITIL) 4 Foundation certification must be completed within 6 months. 

• Exceptional oral and written communication skills, capable of delivering clear, concise technical and management-level reporting across all organizational levels. 

• Excellent interpersonal skills with the ability to work independently, prioritize tasks, and manage multiple initiatives with minimal supervision. 

• Strong analytical and problem-solving capabilities, with a proven track record of designing and implementing effective solutions for complex enterprise IT environments. 

• Advanced expertise in Microsoft and Linux system administration, including installation, configuration, patch management, and performance optimization across both platforms. 

• Extensive experience managing VMware environments, including advanced clustering, configuration, and administration of vSphere, ESXi, and vCenter. 

• Comprehensive knowledge of Active Directory, Microsoft Exchange, Microsoft 365, and enterprise storage solutions, including user and access management, Group Policy, and directory synchronization. 

• Deep understanding of network security protocols and access controls, with hands-on experience configuring and managing firewalls, VPNs, IDS/IPS solutions, and network encryption technologies. 

• Advanced proficiency with enterprise security tools and vulnerability management platforms (e.g., Nessus, Tenable.SC), and thorough understanding of compliance frameworks such as DISA STIGs and NIST SP 800-53.

Competitive salary and benefits package, including:

• Health, dental and vision insurance
• 401(k) with company match
• Paid time off (PTO) for vacation, sick leave, and personal days
• Professional development reimbursement
• Other benefits, including life insurance, disability insurance, and employee assistance programs