Windows Systems Admin III (Corona)

Apex Systems; Norco (CA); On-site; USD 114,000 - 133,000; Full time

Job summary

Apex Systems seeks a seasoned Systems Administrator SME to support a federal defense program with NSWC Corona in Norco, CA. The role focuses on administering and securing Windows and Linux environments, with leadership in infrastructure upgrades and cybersecurity initiatives.

Responsibilities include patching, configuration management, performance monitoring, and documentation. The candidate will work with ISSO and program stakeholders to ensure compliance and reliability in a mission-critical

Qualifications

• 12+ years of systems administration experience with server management, storage, patching, and upgrades.
• DoD 8570 IAT Level II certification is required.
• Experience administering enterprise Windows and Linux/Unix environments and securing IT infrastructure.

Responsibilities

• Administer, maintain, and support Windows and Linux/Unix environments including servers, storage, and network infrastructure.
• Provide SME leadership on infrastructure upgrades, security initiatives, and incident response.
• Install, patch, upgrade hardware/software and enterprise applications.
• Monitor performance, troubleshoot complex issues, and implement corrective actions.
• Maintain network security technologies and support IA, IAV remediation and accreditation activities.
• Develop and maintain IT policies, procedures, and operational documentation.
• Provide Tier II/III support and training for end users on enterprise apps and systems.
• Engage in project planning and future IT improvements.

Skills

Windows server administration

Linux/Unix administration

Active Directory

Security best practices

Vulnerability remediation

Documentation

Education

Bachelor’s Degree in a related field

Master’s Degree in a related field

High School Diploma + 12+ years experience

Tools

DoD 8570 IAT Level II

Patch management tools

Vulnerability scanners

Job description

# Windows Systems Admin III (Corona)Apply**Job#: 3046527****Job Description:**Apex Systems is seeking a highly experienced **Systems Administrator Subject Matter Expert (SME)** to support a federal defense program with **NSWC Corona** in Norco, CA. This individual will serve as a senior technical resource responsible for administering, securing, optimizing, and modernizing enterprise IT infrastructure within a mission-critical environment. The ideal candidate will possess deep expertise across systems administration, network operations, cybersecurity, and server management, while collaborating closely with engineers, cybersecurity teams, and program stakeholders.If interested, please forward resume + certifications to Rich at [e-mail]: CoronaContract: 6 month to PermPay Rate/Salary: $55 - $64 // $115k - $135kClearance: SecretCertifications: IAT IIKey Responsibilities* Administer, maintain, and support enterprise Windows and Linux/Unix environments, including workstations, servers, storage systems, and network infrastructure.* Serve as a technical SME for systems and network operations, providing leadership on infrastructure improvements, upgrades, and security initiatives.* Install, configure, patch, and upgrade hardware, software, operating systems, and enterprise applications.* Monitor system performance, troubleshoot complex hardware, software, and network issues, and implement corrective actions.* Maintain and enhance network security technologies, including firewalls, antivirus solutions, and intrusion detection/prevention systems.* Support cybersecurity compliance efforts, vulnerability remediation, Information Assurance Vulnerabilities (IAVs), and accreditation activities alongside the ISSO.* Manage network accounts, user access, system documentation, and configuration management activities.* Develop and maintain IT policies, procedures, and operational documentation.* Provide Tier II/III technical support and training for end users on enterprise applications and systems.* Evaluate and implement system enhancements to improve reliability, performance, and security.* Support organizational service requests through shared IT support channels and ensure timely issue resolution.* Maintain data integrity and system availability through proactive monitoring and maintenance.* Contribute to status reporting, project planning, and future IT infrastructure recommendations.Required Qualifications**Education & Experience (one of the following):*** High School Diploma/GED + 12+ years of systems administration experience, including 5+ years supporting server management, storage strategies, patching, and system upgrades; OR* Bachelor’s Degree in a related field + 8+ years of systems administration experience, including 3+ years supporting patch management, server operations, and enterprise infrastructure; OR* Master’s Degree in a related field + 5+ years of systems administration experience.Required Technical Skills* Enterprise Windows and Linux/Unix administration* Server deployment, patching, upgrades, and lifecycle management* Network infrastructure support and troubleshooting* Firewalls, antivirus, intrusion detection/prevention technologies* Active Directory and account management* Microsoft Office Suite support* Vulnerability remediation and cybersecurity best practices* Hardware/software troubleshooting and root cause analysis* System monitoring and performance optimization* Technical documentation and process developmentCertifications* **DoD 8570 IAT Level II Certification (Required)** *Everforth Apex is a world-class IT services company that serves thousands of clients across the globe. When you join Everforth Apex, you become part of a team that values innovation, collaboration, and continuous learning. We offer quality career resources, training, certifications, development opportunities, and a comprehensive benefits package. Our commitment to excellence is reflected in many awards, including ClearlyRateds Best of Staffing in Talent Satisfaction in the United States and Great Place to Work in the United Kingdom and Mexico.**Everforth Apex uses a virtual recruiter as part of the application process. Click here for more details. By applying for this job, you agree to receive calls, AI-generated calls, text messages, or emails from Everforth Apex and its affiliates, and contracted partners. Frequency varies for text messages. Message and data rates may apply. Carriers are not liable for delayed or undelivered messages. You can reply STOP to cancel and HELP for help. You can access our privacy policy at https://www.apexsystems.com/privacy-policy**Everforth Apex Benefits Overview: Everforth Apex offers a range of supplemental benefits, including medical, dental, vision, life, disability, and other insurance plans that offer an optional layer of financial protection. We offer an ESPP (employee stock purchase program) and a 401K program which allows you to contribute typically within 30 days of starting, with a company match after 12 months of tenure. Everforth Apex also offers a HSA (Health Savings Account on the HDHP plan), a SupportLinc Employee Assistance Program (EAP) with up to 8 free counseling sessions, a corporate discount savings program and other discounts. In terms of professional development, Everforth Apex hosts an on-demand training program, provides access to certification prep and a library of technical and leadership courses/books/seminars once you have 6+ months of tenure, and certification discounts and other perks to associations that include CompTIA and IIBA. Everforth Apex has a dedicated customer service team for our Consultants that can address questions around benefits and other resources, as well as a certified Career Coach. You can access a full list of our benefits, programs, support teams and resources within our ‘Welcome Packet’ as well, which an Everforth Apex team member can provide.**Everforth Apex Systems is an equal opportunity employer. We do not discriminate or allow discrimination on the basis of race, color, religion, creed, sex (including pregnancy, childbirth, breastfeeding, or related medical conditions), age, sexual orientation, gender identity, national origin, ancestry, citizenship, genetic information, registered domestic partner status, marital status, disability, status as a crime victim, protected veteran status, political affiliation, union membership, or any other characteristic protected by law. Everforth Apex will consider qualified applicants with criminal histories in a manner consistent with the requirements of applicable law.**If you require an accommodation under the Americans with Disabilities Act to participate in an interview with a virtual recruiter or to use our website for a search or application, please contact our Benefits Department at [e-mail] or 804-523-8228. Please note that this contact information is strictly to be used for medical ADA accommodations and that no other inquiries will be answered.**UnitedHealthcare creates and publishes the Transparency in Coverage Machine-Readable Files on behalf of Everforth Apex Systems.***Employee Type:** Contract**Location:** Norco, CA, US**Job Type:****Date Posted:** August 14, 2026**Pay Range:** $55 - $64 per hour