Sr Systems Administrator - TS/SCI clearance

Dunhill Professional Search & Government Solutions; Arlington (VA); Hybrid; USD 120,000 - 180,000; Full time

Job summary

Dunhill Professional Search & Government Solutions in Arlington, VA is seeking a Senior System Administrator to lead the administration, security, and resilience of enterprise IT infrastructure in a federal, hybrid environment. The role requires hands-on expertise across Windows, Linux, virtualization, cloud, and on-site/on-call support. Candidates must hold a TS/SCI clearance and U.S.

citizenship. You will design recovery plans, develop automation, mentor staff, and coordinate incident response

Qualifications

• Bachelor’s degree in IT/CS or equivalent experience.
• 7–10 years of enterprise systems admin experience.
• Experience with Windows, Linux, and cloud environments.
• Expertise in backup, patch management, and config management.
• Scripting in PowerShell, Bash, or Python for automation.
• Current TS/SCI clearance and U.S. citizenship.

Responsibilities

• Engineer and maintain Windows, Linux, cloud and hybrid server environments.
• Lead troubleshooting of failures and performance issues to restore service.
• Design backup, DR, and continuity procedures for critical infrastructure.
• Maintain secure baselines, patching strategies, and access controls.
• Develop automation for provisioning, monitoring, and configuration management.
• Analyze logs and capacity trends to optimize performance.
• Lead incident response and coordinate across teams.
• Review changes for security and recoverability; provide guidance.
• Mentor junior admins and support on-call escalations.

Skills

Windows Server

Linux

Virtualization

Cloud (AWS/Azure)

Automation (PowerShell/Bash/Python)

Security/compliance

Disaster Recovery

On-call support

Scripting

Root cause analysis

Education

Bachelor’s degree in IT/CS or equivalent experience

Tools

PowerShell

Bash

Python

VMware

AWS

Azure

Windows Server

Job description

Outstanding opportunity to support a major federal agency with emerging technology initiatives, including AI implementation! This is a hybrid role working on-site 3 days/week in Arlington VA area. Candidates must have a current TS/SCI clearance.

The Senior System Administrator leads the administration, maintenance, security, and operational resilience of complex enterprise infrastructure supporting mission‑critical systems in a remote federal IT environment. This role provides advanced troubleshooting, capacity planning, configuration management, automation, and patch governance across production Windows, Linux, virtualized, cloud, and hybrid platforms. The Senior System Administrator establishes technical procedures, evaluates system performance and security risks, and guides corrective actions for high‑impact incidents while serving as an escalation resource and technical advisor to other administrators.

Key Responsibilities

• Engineer, configure, and maintain complex Windows, Linux, virtualized, cloud, and hybrid server environments to meet stringent availability, performance, and security requirements across the client enterprise.
• Lead advanced troubleshooting of system failures, performance degradation, authentication issues, integration problems, and hardware or software interoperability defects, driving rapid restoration of service.
• Design and validate backup, restoration, redundancy, disaster recovery, and continuity procedures for critical infrastructure and data, ensuring reliable recovery and minimal downtime.
• Establish and maintain secure configuration baselines, patching strategies, vulnerability remediation priorities, and privileged‑access controls aligned with organizational security and compliance requirements.
• Develop advanced PowerShell, Bash, Python, or comparable automation to support provisioning, compliance validation, monitoring, reporting, and configuration management at scale.
• Analyze logs, performance trends, capacity metrics, and security alerts to anticipate service degradation and recommend infrastructure improvements and optimization actions.
• Lead technical incident response, root‑cause analysis, corrective‑action planning, and restoration activities for high‑priority outages or security events, coordinating across technical teams.
• Review system changes, technical designs, operating procedures, and implementation plans for risk, supportability, security, and recoverability, providing senior technical guidance.
• Mentor junior administrators, coordinate work across technical teams, and serve as a senior escalation point during on‑call operations to ensure continuous platform availability.

Required Qualifications

• Bachelor’s degree in Information Technology, Computer Science, or a related field, or equivalent relevant experience.
• 7-10 years of progressively responsible experience in systems administration or infrastructure engineering, including advanced work with enterprise Windows, Linux, and virtualized/cloud environments.
• Demonstrated experience administering and securing mission‑critical systems in an enterprise or federal IT environment, including backup/recovery, patch management, and configuration management.
• Strong expertise in scripting and automation (e.g., PowerShell, Bash, Python) to streamline provisioning, patching, monitoring, and compliance tasks.
• Proven ability to perform root‑cause analysis and resolve complex hardware, software, and networking issues with minimal supervision.
• Must have a current TS/SCI clearance; U.S. citizenship required for the role.
• Advanced cybersecurity certification such as CompTIA Security+, CASP+, or equivalent.
• Experience working in on‑call or 24/7 support models for high‑availability infrastructures.

Preferred Qualifications

• Advanced platform certifications in Microsoft, Linux, virtualization, or major cloud providers (e.g., AWS, Azure).
• Experience administering infrastructure within classified or highly regulated government environments.
• Prior experience leading technical teams or acting as a senior escalation point for systems and infrastructure operations.