**MANTECH** seeks a motivated, career and customer-oriented **Linux System Administrator** to join our team. This is a remote position. Our mission is to support Linux-based computer systems that process military medical records. This is primarily an operations and sustainment role for the live Production environment. Also includes some lower environments, and some DevOps work as we build out new infrastructure and make progress towards containerizing our systems. **Responsibilities include but are not limited to:** + Troubleshoot and resolve issues with applications/servers, in a complex, ever-changing environment, without requiring a step-by-step guide; handle intense, high-stress, highly visible projects, mostly alone, without needing constant guidance and find the root cause, understand the problem and the environment, determine and present options for a permanent fix, get buy-in from relevant parties, and implement. + Perform system setup, configuration, and routine maintenance tasks on various Linux distributions, including user account management, software installation, and system updates; set up and manage monitoring tools and respond to alerts promptly. + Automation and Scripting: Develop and maintain shell scripts and automation tools to streamline system management and administrative tasks. + Security and Compliance: Implement and maintain security best practices, including firewalls, access controls, and vulnerability assessments. Ensure compliance with industry standards and regulations. + Configure and troubleshoot network services, TCP/IP, DNS, DHCP, and routing. Collaborate with network engineers to optimize network performance; collaborate with cross-functional teams and IT professionals to resolve technical issues and contribute to IT projects and initiatives. + Fine-tune system performance through kernel optimization, resource monitoring, and load balancing and maintain accurate and up-to-date documentation of system configurations, processes, and procedures; establish and maintain backup and disaster recovery solutions. Test and refine recovery procedures regularly. + Utilize Kubernetes to plan, implement, and maintain Kubernetes infrastructure. Utilize Rancher as a K8s frontend and GitLab for version control of Helm charts and pipelines to automatically build/deploy our applications. **Minimum Qualifications:** + 7+ years of relevant experience as a Linux Systems Administrator, with proficiency in managing various Linux distributions. Bachelor’s degree may be substituted for 4 years of experience. + Expertise in Kubernetes/Rancher/GitLab architecture – build complex K8s ingresses (including URL rewriting, redirecting incoming requests to external systems rather than a Kubernetes pod, and 2-way SSL throughout). Understand Helm charts and utilize GitLab for version control of Helm charts. Configure pipelines within GitLab for automated building of applications and automated deployment to the containerized environment and troubleshoot the pipelines when something breaks. Be familiar with Rancher as a K8s frontend. + Strong performance as a Linux administrator – build/configure/manage Linux servers from the command line (don't be reliant on a GUI). Write shell scripts for automation and task simplification. Know Linux security best practices and how to harden systems. Be familiar with network protocols, routing, and firewall configuration. Pick up and retain new technical skills as needed. Also be able to function in a Windows environment. + Strong demonstrated ability in application troubleshooting – troubleshoot and resolve issues with applications/servers, in a complex, ever-changing environment, without requiring a step-by-step guide. Get to the root cause, understand the problem and the environment, determine and present options for a permanent fix, get buy-in from relevant parties, and implement. + Communication skills (both written and verbal) and customer service skills – function as part of a team and accept direction/correction. Represent our team in meetings with senior/executive level staff, government contacts, and external partners. Keep stakeholders informed. Document your work. + Work independently when required – be able to handle difficult, high-stress, highly visible projects, without relying on frequent guidance. **Preferred Qualifications:** + Experience working in an application troubleshooting or IT sustainment role, which supported a government contract or a live Production environment. + Expertise in Bash scripting, Ansible, JBoss, SQL, Kubernetes/Rancher, AppDynamics, GitLab pipelines or other CI/CD tools, and/or Java or Python programming. + Education and/or technical certifications in a relevant field. **Clearance Requirements:** + Must be a U.S. citizen and have current/active Secret clearance. **Physical Requirements:** + Must be able to be in a stationary position more than 50% of the time + Constantly operates a computer and other office productivity machinery, such as a computer + The person in this position frequently communicates with co-workers, management and clients, which may involve delivering presentations ad must be able to exchange accurate information in these situations + The person in this position needs to occasionally move about inside the office to access file cabinets, office machinery, etc. ManTech International Corporation, as well as its subsidiaries proactively fulfills its role as an equal opportunity employer. We do not discriminate against any employee or applicant for employment. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, or status as a protected veteran. If you are a qualified individual with a disability and require a reasonable accommodation to apply for a position with ManTech through its online applicant system, please email us at careers@mantech.com and provide your name and contact information.