Lead Systems Administrator

Remote from: USA
Salary, yearly, USD: 137,100 - 244,100
Department: DevOps & Infrastructure
Employment type: Full Time,
Job posted: 19 May 2026
Apply before: 19 Jun 2026
Experience level: Senior
Views / Applies: 7 / 2

ManTech delivers technology-driven innovation, develops game-changing solutions, and delivers mission-focused technologies for defense and federal civilian agencies.

Defense & Space
1968

Actively Hiring

AI Summary

MANTECH seeks a Lead Systems Administrator for the CASTLE-NET Program, supporting the USACE OCIO/G-6. This remote role involves managing Windows, Linux, and VMware environments, leading technology assignments, and ensuring IT infrastructure reliability and security. Candidates need 8+ years of experience, a Secret clearance, and relevant certifications. The position offers a competitive salary range of $137,100-$244,100 annually.

Job Complexity

Easy Hard

AI Insight The role requires extensive experience (8+ years), leadership skills, and multiple certifications including DoD 8140 IAT Level II, making it challenging but not the highest difficulty due to remote work flexibility.

Salary Analysis

AI Insight The offered salary range of $137,100-$244,100 is significantly above the US market median for Lead Systems Administrators ($150,000-$170,000), reflecting the specialized DoD requirements and security clearance. The midpoint of $190,600 is highly competitive, especially for a remote position.

Key Skills

Systems Administration Windows Server Linux VMware vSphere PowerShell Python Security Clearance DoD 8140 IT Infrastructure Leadership

Cover Letter Sample

Dear Hiring Manager,

I am excited to apply for the Lead Systems Administrator position with MANTECH on the CASTLE-NET Program. With over 8 years of experience in systems administration across Windows, Linux, and VMware environments, I have developed a strong foundation in managing complex IT infrastructures. My background includes leading technology projects, optimizing system performance, and ensuring security compliance, which aligns perfectly with the responsibilities outlined in the job description.

I hold a Bachelor's degree in Information Technology and possess certifications including Microsoft Certified: Windows Server and RHCSA. Additionally, I maintain a DoD 8140 IAT Level II certification and an active Secret clearance. My proficiency in scripting languages such as PowerShell and Python has enabled me to automate routine tasks and improve operational efficiency.

I am particularly drawn to MANTECH's mission of supporting the Department of Defense and would welcome the opportunity to contribute to your team. Thank you for considering my application. I look forward to the possibility of discussing how my skills and experiences can support the CASTLE-NET Program.

Sincerely,
[Your Name]

Possible Interview Questions

Describe your experience managing both Windows and Linux servers in a single environment. How do you ensure compatibility and security across platforms?

I have managed mixed environments using tools like Active Directory for Windows and LDAP for Linux, with centralized patch management via WSUS and Red Hat Satellite. I ensure security by applying consistent policies through Group Policy and configuration management tools like Ansible, and by conducting regular vulnerability scans.

Can you explain a complex project you led involving virtualization? What challenges did you face and how did you overcome them?

I led a migration of 200 VMs from an older vSphere cluster to a new one. Challenges included minimizing downtime and ensuring data integrity. I used VMware vMotion for live migration, coordinated with teams for maintenance windows, and performed thorough testing post-migration.

How do you stay current with DoD 8140 requirements and maintain your certifications?

I track certification renewal timelines and complete continuing education through courses on platforms like FedVTE and SANS. I also participate in webinars and read industry publications to stay updated on evolving compliance standards.

Describe a time you had to troubleshoot a critical system failure. What was your approach?

During a critical outage of a file server, I first isolated the issue to a failed RAID controller. I restored services from backup onto a spare server, then coordinated with hardware vendor for replacement. I documented the incident and implemented monitoring alerts to prevent recurrence.

How do you prioritize tasks when managing multiple projects and support requests?

I use a ticketing system to categorize requests by urgency and impact. For projects, I break them into milestones with deadlines. I communicate with stakeholders to set expectations and adjust priorities as needed, ensuring critical issues are addressed first.

General information

Requisition # R67820 Locations USA-Remote Work Posting Date 05/18/2026 Security Clearance Required Secret Remote Type Fully Remote Time Type Full time

Description & Requirements

Shape the future of defense with MANTECH! Join a team dedicated to safeguarding our nation through advanced tech and innovative solutions. Since 1968, we’ve been a trusted partner to the Department of Defense, delivering cutting-edge projects that make a real impact. Dive into exciting opportunities in Cybersecurity, IT, Data Analytics and more. Propel your career forward and be part of something extraordinary. Your journey starts now—protect and innovate with MANTECH!

MANTECH seeks a motivated, career and customer-oriented Lead Systems Administrator to join our CASTLE-NET Program team. This is a remote position.

Be a part of an agile team to provide innovative, customer focused, and cost-effective integrated enterprise IT support services in support of the client’s vision of engineering solutions for the Nation’s toughest challenges.

Responsibilities include but are not limited to:

Managing and maintaining the IT infrastructure to ensure reliability, performance, and security across Windows, Linux, and VMware environments.
Planning and leading major technology assignments while providing leadership to ensure technical requirements and project objectives are met.
Installing, configuring, and supporting servers and virtualized environments in close coordination with IT teams, application developers, and stakeholders.
Evaluating performance results and recommending major changes that affect short-term project growth and overall success.
Interfacing with senior management regarding decision-making and domain knowledge that may have a critical impact on project implementation.
Delivering world-class IT services and responsive customer support to exceed the expectations of USACE OCIO/G-6 IT end-users.
Functioning as a technical expert across multiple project assignments to deliver secure, innovative, and modernized technological solutions.

Minimum Qualifications:

Bachelor’s degree in Information Technology or related field; or an Associate degree with 10+ years of experience; or 12+ years of relevant experience.
Requires 8+ years of progressively responsible experience in systems administration for Windows, Linux, or VMware environments.
Comprehensive knowledge of operating systems such as Windows Server, Red Hat, and CentOS, as well as virtualization technologies like VMware vSphere.
Proficiency in scripting languages including PowerShell, Bash, or Python, and experience with system monitoring and performance tuning.
Experience creating, maintaining, and communicating complex information technology documentation and system configurations.
Possession and maintenance of relevant certifications such as Microsoft Certified: Windows Server, RHCSA, RHCE, or VCP.
Must maintain a DoD 8140 IAT Level II certification to comply with mission security and baseline requirements.

Preferred Qualifications:

Familiarity with the USACE IT environment, regulatory requirements, and data security best practices.

Clearance Requirements:

Must possess a Secret security clearance prior to starting this position.

Physical Requirements:

The person in this position must be able to remain in a stationary position 50% of the time. Occasionally move about inside the office to access file cabinets, office machinery, or to communicate

The projected compensation range for this position is $137,100.00-$244,100.00. There are differentiating factors that can impact a final salary/hourly rate, including, but not limited to, Contract Wage Determination, relevant work experience, skills and competencies that align to the specified role, geographic location (For Remote Opportunities), education and certifications as well as Federal Government Contract Labor categories. In addition, MANTECH invests in its employees beyond just compensation. MANTECH’s benefits offerings include, dependent upon position, Health Insurance, Life Insurance, Paid Time Off, Holiday Pay, short-term and long-term Disability, Retirement and Savings, Learning and Development opportunities, wellness programs as well as other optional benefit elections.
MANTECH 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 [email protected] and provide your name and contact information.

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