Senior Linux System Administrator

Description Are you passionate about shaping secure, IT systems in classified environments? Do you want to influence system improvements, implementation decisions, and the overall security posture of advanced technology systems? If so, we're looking for someone like you to join our team at APL! We are seeking a Linux System Administrator to join the RF Engineering group to support Hardware‑in‑the‑Loop (HiL) facilities. In this role, you will apply Risk Management Framework (RMF) principles, develop new IT security capabilities, and provide advanced system administration across complex, classified infrastructures, helping drive innovation, security, and operational excellence. This role combines technical execution, collaborating with a team of system administrators, and establishing Linux standards. As a Linux system administrator, you will recommend and implement changes that align with security protocols, the overall mission, and engineering team capabilities. Responsibilities Plan, deploy, maintain, and upgrade computing and networking infrastructure supporting HiL operations, including legacy platforms, modern platforms, and real‑time computing systems. Design, implement, and enforce system security hardening standards (STIG) in accordance with established compliance frameworks (RMF, NIST, etc.). Support installation and management of engineering, scientific, and analysis applications in secure, classified environments such as GitLab and MATLAB. Solve complex technical issues that impact system availability, performance, or security. Integrate Linux systems with Windows platforms to support hybrid workflows in RF and simulation environments. Manage a lab/test environment to validate new applications, configurations, and upgrades before deployment to production systems. Collaborate with engineers, cybersecurity staff, and program managers to ensure mission success. Qualifications Have a Bachelor’s degree in Computer Science, Information Technology, or related field, or have equivalent experience. Possess 7+ years of professional experience as a Linux systems administrator in secure or complex environments. Are a strong teammate with a focus on exchanging information and collaboration. Are proficient in various operating systems, including Linux (RHEL5‑RHEL9, Ubuntu) and real‑time Linux computing systems. Have knowledge of interoperability between Linux and Windows systems. Have experience administering systems in classified environments, with an understanding of secure operations, auditing, and compliance frameworks (RMF, NIST, etc.). Have excellent written and verbal communication skills with the ability to collaborate across engineering, program, and security teams. Are proactive, self‑motivated, and comfortable owning technical decisions. Have some experience with programming/scripting languages. Hold a current DoD 8570 certification (Security+, CASP, CISSP) or have the ability to obtain one within six months of employment. Hold an Interim Secret level security clearance and can ultimately obtain a Top‑Secret level clearance. Eligibility includes U.S. citizenship and a government security clearance investigation. About Us The Johns Hopkins University Applied Physics Laboratory (APL) brings world‑class expertise to our nation’s most critical defense, security, space and science challenges. While we are dedicated to solving complex challenges and pioneering new technologies, what makes us truly outstanding is our culture. We offer a vibrant, welcoming atmosphere where you can bring your authentic self to work, continue to grow, and build strong connections with inspiring teammates. At APL, we celebrate our differences of perspectives and encourage creativity and bold, new ideas. Our employees enjoy generous benefits, including a robust education assistance program, unparalleled retirement contributions, and a healthy work/life balance. APL’s campus is located in the Baltimore‑Washington metro area. Learn more about our career opportunities at All qualified applicants will receive consideration for employment without regard to race, creed, color, religion, sex, gender identity or expression, sexual orientation, national origin, age, physical or mental disability, genetic information, veteran status, occupation, marital or familial status, political opinion, personal appearance, or any other characteristic protected by applicable law. APL is committed to providing reasonable accommodation to individuals of all abilities, including those with disabilities. If you require a reasonable accommodation to participate in any part of the hiring process, please contact View email address on click.appcast.io. Minimum Rate $100,000 Annually Maximum Rate $245,000 Annually #J-18808-Ljbffr Johns Hopkins Applied Physics Lab