Linux Systems Administrator

Linux Systems Administrator

Job Type: Full-Time
Location: Killeen, Texas
Department: Systems Support

Job Summary

We are looking for an experiencedLinux Systems Administrator to administer, monitor, secure, and maintain enterprise Linux environments. The ideal candidate will have strong hands-on experience withRHEL, Ubuntu, and CentOS, along with familiarity with Windows Server, VMware, and containerized environments such as OpenShift and Kubernetes.

This role will provide Tier 2/3 technical support, troubleshoot complex infrastructure issues, support enterprise applications, and collaborate closely with development, DevOps, and security teams.

Key Responsibilities

• Administer, monitor, maintain, and troubleshootLinux systems, including RHEL, Ubuntu, and CentOS.
• Install, configure, secure, and optimize Linux services such assystemd, SSH, Apache/Nginx, cron, and related services.
• Perform Linux system upgrades, patching, configuration, and security hardening.
• ProvideTier 2/3 support for escalated server and infrastructure issues.
• Identify, research, and implement Linux andOpenShift solutions and applications.
• Support and troubleshoot enterprise applications and their underlying server environments.
• Manage Linux security administration in collaboration with information security teams.
• Monitor system health, performance, availability, and capacity, and proactively address potential issues.
• Collaborate with development, DevOps, infrastructure, and security teams to support application and infrastructure requirements.
• Provide technical guidance and support to IT teams on Linux configuration and administration.
• Maintain awareness of Linux and OpenShift updates, changes, and new releases, and communicate relevant changes to stakeholders.
• Work with vendors and internal teams to resolve technical issues and support applications and infrastructure.
• Create and maintain accurate technical documentation, processes, and standard operating procedures.
• Participate in aweekly on-call rotation to respond to after-hours infrastructure issues.
• Travel to other data centers or company locations as required.
• Perform other duties and assignments as needed.

Windows Server & Virtualization

• Provide administration and support forWindows Server environments and related services.
• Working knowledge ofActive Directory, Group Policy, DNS, DHCP, and PowerShell.
• AdministerVMware vSphere/ESXi environments, including:
  • Virtual machine deployment
  • Resource management
  • VM administration
  • Snapshots
  • Basic troubleshooting

OpenShift & Containerization

• Support and administerOpenShift/Kubernetes environments.
• Install, configure, maintain, upgrade, monitor, and troubleshoot OpenShift/Kubernetes clusters.
• Support containerized applications usingOpenShift, Kubernetes, or Docker.
• Stay current with developments, updates, and best practices in container orchestration technologies.

Security & Compliance

• Ensure compliance with security standards, patching schedules, and organizational policies.
• Apply security hardening practices to Linux and server environments.
• Understand commonweb application and infrastructure vulnerabilities, risks, and appropriate countermeasures.
• Work closely with security teams to identify and remediate security issues.
• Maintain confidentiality of sensitive customer, business, and internal information.

Required Qualifications & Skills

• Bachelor's degree inComputer Science, Computer Engineering, Information Technology, or a related field preferred. Equivalent relevant experience may be considered.
• Strong hands-on experience administeringLinux servers, preferably RHEL, Ubuntu, and/or CentOS.
• Strong troubleshooting and analytical skills with the ability to independently research and resolve complex technical issues.
• Experience with Linux system administration, configuration, patching, and security.
• Knowledge of Windows Server administration and core services.
• Familiarity with VMware vSphere/ESXi.
• Knowledge of web/application server technologies such as Apache and Nginx.
• Understanding of server and web application security principles.
• Ability to manage multiple priorities and meet project deadlines.
• Strong written and verbal communication skills.
• Ability to collaborate effectively with technical and non-technical stakeholders.
• Ability to work independently as well as part of a broader IT team.
• Willingness to participate in an on-call rotation.

Preferred Qualifications

• Experience withOpenShift, Kubernetes, and/or Docker.
• Experience installing, configuring, upgrading, monitoring, and troubleshooting OpenShift/Kubernetes clusters.
• Familiarity withCI/CD pipelines, Git, and DevOps practices.
• Experience withInfrastructure as Code (IaC) tools such asTerraform and Ansible.
• Experience with monitoring and logging platforms such asPrometheus, Grafana, ELK, or Splunk.
• Familiarity with Linux security hardening and patch management.
• Certifications such asRHCSA, RHCE, CKA, CKAD, or OpenShift certifications are a plus.

What We're Looking For

We are looking for someone who is technically strong, security-conscious, and comfortable working across Linux infrastructure, virtualization, and modern containerized environments. The ideal candidate should be proactive, capable of handling complex production issues, and able to collaborate effectively across IT, DevOps, development, and security teams.

About ISHIR

ISHIR is a digital innovation and enterprise AI services provider. We work with startups and enterprises to shape the future through accelerated innovation, deep technical expertise, access to global digital talent and a passion for complex problem-solving. With our help, our clients overcome their most difficult digital challenges leveraging AI.

We are not just consultants, we are partners in our clients’ success, assisting them with re(gaining) competitive edge by identifying opportunities for differentiation, industry disruption, scalable innovation, and go-to-market strategies that deliver successful outcomes.

At ISHIR, we help bold businesses accelerate innovation through Talent, Speed-to-Market, and AI. We help make an impact by solving real problems using innovation, improved customer experiences and the right technologies.

As an ISHIR employee, you will get the advanced training you need to be successful, and the opportunity to apply it. You must be passionate about technology, crave responsibility, and be eager to apply your knowledge to real business solutions for our startup and enterprise customers. These are the qualities of a person destined for success at ISHIR.

ISHIR attracts a special type of individual—someone who is proactive, thrives on challenges, feeds off success, and looks at moving targets not as obstacles but as opportunities. ISHIR is an exciting place to work. It is imbued with an entrepreneurial spirit and promotes self-reliance, open communication, and collaboration.