Senior System Administrator

Mitre Corporation; El Segundo (CA); On-site; USD 99,000 - 149,000; Full time

Job summary

MITRE is seeking a Systems Administrator to deploy, operate, and maintain IT systems in a classified Los Angeles lab environment. The role requires hands-on work with Windows/Linux, VMware/Hyper-V, and backups, in a secure setting.

Preferred candidates hold TS/SCI clearance or active clearance with CI poly, and experience in a fast-paced, on-site environment. This full-time position supports mission-critical programs and requires collaboration with security and facilities teams.

Qualifications

• Minimum 5 years of related experience with a Bachelor’s degree; or 3 years and a Master’s degree; or a PhD with relevant experience who can immediately contribute at this job step; or equivalent combination of related education and work experience.
• Active Top Secret U.S Government issued Security Clearance with the ability to obtain and maintain a Top Secret/SCI clearance; U.S. citizen required.
• On-site requirement of 5 days a week at the Los Angeles, CA facility and ability to coordinate with security and facilities teams.

Responsibilities

• Deploy, operate, and maintain IT systems in a classified lab environment.
• Patch and update Windows and Linux servers and desktops (RHEL, Ubuntu).
• Manage VMware ESXi, Proxmox, and Hyper-V platforms.
• Maintain backup and recovery systems such as Commvault.
• Coordinate equipment installation, disposition, and audits with security and facilities teams.
• Support Site Operations and escort cleared/uncleared visitors.

Skills

Server & desktop OS knowledge

Lab IT architecture understanding

Network & OS hardening

Command-line proficiency

Customer service

Collaboration

Security clearance

On-site work commitment

Education

Bachelor’s degree

Master’s degree

PhD

Tools

VMware ESXi

Proxmox

Hyper-V

Commvault

GitLab

Prometheus/Grafana

Docker

VSCode

PyPI mirrors

SIEMs

Job description

At MITRE, your passion fuels work that impacts our nation and improves lives. This is where your skills strengthen national security, cybersecurity, health, transportation, and citizen services. We’re a nonprofit engineering, applied research, and advanced technology organization working in the public interest. With objectivity and integrity at our core, we lead federally funded research and development centers for U.S. government agencies – collaborating with industry and academia to deliver integrated, high-impact solutions that advance our nation’s health, security, and prosperity. Our people tackle the toughest technical challenges, supported by competitive benefits, meaningful career development, and a culture of innovation, collaboration, and technical excellence. Choose MITRE for a career with purpose — and help shape the future.

The R310 Classified Systems Engineering Department delivers secure, mission-critical information technology services for classified research and operations, ensuring highly controlled computing environments remain reliable, compliant, and available.

The department designs, operates, and sustains classified infrastructure, including systems, networks, storage, and access controls, while meeting stringent security and regulatory requirements. In parallel, R310 actively reduces risk and technical debt, mitigates compliance drift, and modernizes platforms to support evolving mission needs, enabling classified programs to execute with confidence, resilience, and operational focus.

Roles & Responsibilities:

The team seeks a full-time Systems Administrator to support the deployment, operation, and maintenance of IT systems in a classified lab environment. This role is best suited for someone who has prior experience working as a classified IT Systems Administrator. This is an on-premises position in our Los Angeles, CA facility. The successful candidate will have experience in:

• Patching and updating Windows and Linux (RHEL, Ubuntu) server and desktop operating systems
• Perform general systems administration (patching, updates, user support) of:
• Windows & Linux desktops and servers
• Network switches (preferred)
• VMware ESXi, Proxmox (Debian), Microsoft Hyper-V platforms
• Network Storage Systems
• Repository mirrors, such as: VSCode, Docker, Pypi
• Backup and recovery/disaster recovery platforms such as Commvault
• Maintenance of other systems/services according to project needs (SIEMs, Gitlab, Prometheus/Grafana and other monitoring tools, miscellaneous web servers, etc.,)
• Building and hardening Windows, Linux, virtualization (VMWare, Proxmox, Hyper-V) systems
• Support procurement, management and accountability of Classified IT hardware and property
• Design future IT infrastructure upgrades to support changing site needs
• Track equipment location, status, and movement into/out of classified spaces; maintain records to support audits and inventories
• Maintain a company purchase card; manage classified equipment and subcontract purchases IAW acquisition policies
• Coordinate equipment installation, disposition, turn-in, or destruction activities as necessary with other Global Security teams and relevant stakeholders
• Plan and execute equipment moves and transfers associated with facility transitions ensuring proper approvals and documentation are maintained
• Support Site Operations team in day-to-day security operations.
• Assist with escorting cleared and uncleared visitors
• Assist in opening and closing the site’s classified spaces
• Monitor power and HVAC status impacting classified spaces; coordinate repairs with facilities manager and assistant site lead during outages; notify affected project personnel of outages, impacts, and restoration timelines

Basic Qualifications:

Typically requires a minimum of 5 years of related experience with a Bachelor’s degree; or 3 years and a Master’s degree; or a PhD with relevant experience who can immediately contribute at this job step; or equivalent combination of related education and work experience.

• Working knowledge of server and client operating systems. (Win11, Srv22/25, RHEL 8+, Ubuntu Linux 22.04+)
• Fundamental understanding of lab IT architecture.
• Fundamental understanding of VOIP and VTC systems and their troubleshooting.
• Fundamental understanding of system administration, network, and operating system hardening techniques.
• Fundamental understanding of operating system command-line tools.
• Ability to interface with customers and provide a high level of customer service both written and verbal.
• Ability to function effectively in a dynamic, fast-paced environment.
• Ability to collaborate effectively with others.
• Must have an active Top Secret U.S Government issued Security Clearance with the ability to obtain and maintain a Top Secret/SCI U.S. Government issued Security Clearance. Per the U.S. Government’s eligibility requirements, you must be a U.S Citizen to be considered for a security clearance.
• This position has an on-site requirement of 5 days a week on-site.

Preferred Qualifications:

• Active TS/SCI with CI Poly Security Clearance.
• Security+ Certification / 8570 Certification – IAT Level II or meets 8140 requirements.
• Experience with one or more programming/scripting languages (Chef, Ansible, Powershell, Bash, Python, etc.).

This requisition requires the candidate to have a minimum of the following clearance(s):

Top Secret

This requisition requires the hired candidate to have or obtain, within one year from the date of hire, the following clearance(s):

Top Secret/SCI

Salary compensation range and midpoint:

$99,200 - $124,000 - $148,800 Annual

Work Location Type:

Onsite

Commitment to Non-Discrimination

All qualified applicants will receive consideration for employment without regard to disability, status as a protected veteran or any other status protected by applicable federal, state, local or international law.

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