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Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Cyber Security Engineer III - **Company:** Mount Indie - **Location:** San Diego, CA, United States - **Experience:** Expert - **Contract:** Permanent contract - **Skills:** Microsoft Windows, Active Directory, Border Gateway Protocol, Configuration Management, CompTIA Network+, CompTIA Security+, Cyber Security, Databases, Data Security, Linux, VMware ESX Servers, Monitoring of Systems, Windows Servers, Routing, Network Virtualization, Open Shortest Path First (OSPF), Red Hat Enterprise Linux, Ansible, Storage Virtualization, Virtualization Technology, Software Vulnerability Management, Wide Area Networks, Enterprise Software Applications, System Availability, Infrastructure Automation Frameworks, Atlassian Tools, Nessus, Veeam, Terraform, Splunk, Devsecops, Wsus, Jenkins - **Published:** September 11, 2026 - **Apply:** https://www.clearancejobs.com/jobs/9155720/cyber-security-engineer-iii ## About the Role * 5+ years of experience in systems administration, infrastructure engineering, network engineering, cybersecurity engineering, or a related technical discipline. * Hands-on experience administering VMware ESXi and vSAN environments. * Experience deploying and maintaining RHEL and Windows Server systems. * Experience with infrastructure automation using Ansible, Terraform, or comparable Infrastructure as Code and configuration-management tools. * Experience implementing or remediating DISA STIG and NIST SP 800-53 security controls. * Strong understanding of enterprise virtualization, secure data center operations, and on-premises or private cloud infrastructure. * Experience managing vulnerability remediation efforts in classified, regulated, or compliance-driven environments. * Experience supporting DoD, Intelligence Community, federal government, or similarly regulated mission systems. * Ability to work across infrastructure, networking, cybersecurity, software, and mission teams within classified environments. * Ability to travel up to 20%. Preferred Skills and Experience: * Previous experience supporting Intelligence Community or national-security organizations. * Experience with LAN/WAN environments, routing, switching, OSPF, and BGP. * Experience with ACAS, Nessus, Splunk, Veeam, Horizon, Dell Wyse, or similar enterprise technologies. * Experience supporting ATO packages, security assessments, compliance documentation, control validation, or cybersecurity audits. * Familiarity with DevSecOps practices and workflows in classified or restricted environments. * Experience with Jenkins, PDQ, WSUS, Active Directory, Atlassian tools, YUM repositories, databases, and enterprise monitoring platforms. * Experience serving as a technical lead, mentoring junior engineers, or coordinating engineering activities across multiple technical teams. Education and Certification Requirements: * Bachelor's or master's degree in a STEM-related field. * CompTIA Security+ certification or ability to obtain within 12 months of hire. * CompTIA Network+ certification or ability to obtain within 12 months of hire. * ITIL Foundation certification. * Additional DoD 8570 or DoD 8140 aligned certifications are preferred. Citizenship and Clearance Requirements: * U.S. Citizenship required. * Dual citizenship is not permitted. * Active Top Secret clearance with SCI eligibility required. ## Description We are seeking a Cybersecurity Engineer III to support secure, mission-critical infrastructure used by government and Intelligence Community customers. This role will work across classified Secret and Top Secret environments and support the engineering, administration, security, and sustainment of complex enterprise systems. The engineer will work across virtualization, Linux and Windows infrastructure, networking, automation, vulnerability management, and compliance-driven security requirements. You will partner with infrastructure, cybersecurity, engineering, and mission teams to maintain reliable systems, resolve technical issues, remediate vulnerabilities, and support environments throughout their development, accreditation, and operational lifecycle., * Design, deploy, administer, and sustain infrastructure supporting classified Secret and Top Secret environments. * Maintain large-scale VMware ESXi and vSAN virtualization environments. * Deploy, configure, patch, and administer RHEL and Windows Server systems. * Implement and remediate security controls aligned with NIST SP 800-53 and DISA STIG requirements. * Automate system provisioning, configuration, patching, and hardening using tools such as Ansible, Jenkins, PDQ, WSUS, and related technologies. * Identify, track, prioritize, and remediate vulnerabilities using ACAS, Nessus, Splunk, and other security platforms. * Support enterprise services including Active Directory, databases, Veeam, Horizon, Atlassian tools, YUM repositories, and monitoring solutions. * Support LAN/WAN and virtual network infrastructure, including troubleshooting routing issues involving OSPF and BGP. * Work closely with cybersecurity, systems, network, software, and mission teams to resolve technical issues and implement secure infrastructure solutions. * Support ATO and accreditation activities, including security documentation, control validation, remediation efforts, and audit support. * Maintain and improve system availability, security posture, configuration consistency, and operational readiness across classified environments. ## Related Videos - [Docker network without Docker](https://www.wearedevelopers.com/videos/1418-docker-network-without-docker) - [What makes Cybersecurity different for critical infrastructure?](https://www.wearedevelopers.com/videos/571-what-makes-cybersecurity-different-for-critical-infrastructure) - [Docker exec without Docker](https://www.wearedevelopers.com/videos/1094-docker-exec-without-docker) - [Security Pitfalls for Software Engineers](https://www.wearedevelopers.com/videos/726-security-pitfalls-for-software-engineers) - [The Developer Workstation Blind Spot: Why Your Security Stack Can't See What Matters Most](https://www.wearedevelopers.com/videos/100254-the-developer-workstation-blind-spot-why-your-security-stack-can-t-see-what-matters-most) - [Discover the open source trio you didn’t expect: .NET and PostgreSQL on Linux](https://www.wearedevelopers.com/videos/2042-discover-the-open-source-trio-you-didn-t-expect-net-and-postgresql-on-linux) ## Related Articles - [9 Ways to Make Money Hacking](https://www.wearedevelopers.com/magazine/333-9-ways-to-make-money-hacking) - [Is Software Engineering Over-Saturated?](https://www.wearedevelopers.com/magazine/418-is-software-engineering-over-saturated) - [How We Built a Worry-Free System That Runs for 10+ Years – And What We’d Do Again](https://www.wearedevelopers.com/magazine/751-how-we-built-a-worry-free-system-that-runs-for-10-years-and-what-we-d-do-again) - [Where to Find Entry-Level Software Engineering Jobs](https://www.wearedevelopers.com/magazine/397-where-to-find-entry-level-software-engineering-jobs) - [What’s the Difference between a Junior, Mid, and Senior Developer?](https://www.wearedevelopers.com/magazine/238-what-s-the-difference-between-a-junior-mid-and-senior-developer) - [Top-Paying Tech Jobs (with Salaries)](https://www.wearedevelopers.com/magazine/372-top-paying-tech-jobs-with-salaries)