Senior Linux System Administrator

ISHIR; Killeen (TX); On-site; USD 90,000 - 120,000; Full time

Job summary

ISHIR is seeking a Linux Systems Administrator to join its Systems Support team in Killeen, TX. You will manage Linux servers (RHEL/Ubuntu/CentOS), secure services, and troubleshoot complex infrastructure while supporting Windows environments and VMware, OpenShift, and Kubernetes in a hands-on capacity.

Ideal candidates will have strong problem-solving skills, be security-conscious, and able to collaborate with DevOps, development, and security teams across locations.

Qualifications

• Experience administering Linux servers (RHEL, Ubuntu, CentOS).
• Linux configuration, patching, troubleshooting, and security experience.
• Working knowledge of Windows Server and core services.
• Familiarity with VMware vSphere/ESXi.
• Experience with Apache/Nginx and web server technologies.
• Understanding of server security and common web app vulnerabilities.
• Strong analytical and independent troubleshooting skills.
• Excellent written and verbal communication skills.
• Ability to collaborate with technical and non-technical stakeholders.
• Willingness to participate in an on-call rotation.

Responsibilities

• Administer, monitor, maintain, and troubleshoot Linux servers (RHEL, Ubuntu, CentOS).
• Install, configure, secure, and optimize Linux services (SSH, systemd, Apache/Nginx, cron).
• Perform system upgrades, patching, security hardening, and configuration management.
• Provide Tier 2/3 support for complex infrastructure and enterprise applications.
• Support OpenShift/Kubernetes environments and containerized apps.
• Administer Windows Server environments (AD, DNS, DHCP, GPO, PowerShell).
• Support VMware vSphere/ESXi, including VM deployment and resource management.
• Monitor performance, availability, capacity, and security.
• Collaborate with development, DevOps, and security teams.
• Maintain technical documentation and SOPs.
• Participate in weekly on-call rotation and travel as required.

Skills

Linux system administration

Windows Server administration

On-call support

DevOps collaboration

Strong communication

Education

Bachelor’s degree in Computer Science or related field

Tools

OpenShift

Kubernetes

Docker

Ansible

Terraform

Git

Prometheus/Grafana

ELK/Splunk

Job description

Linux Systems Administrator | Killeen, Texas | Full-Time

We’re Hiring: Linux Systems Administrator

Location: Killeen, Texas

Job Type: Full-Time

Department: Systems Support

Are you an experienced Linux Systems Administrator with strong hands‑on expertise in enterprise infrastructure, server security, and troubleshooting? We’re looking for a technically skilled professional to join our Systems Support team and help maintain, secure, and optimize enterprise IT environments.

What You’ll Be Doing

• Administer, monitor, maintain, and troubleshoot Linux servers (RHEL, Ubuntu, and CentOS).
• Install, configure, secure, and optimize Linux services, including SSH, systemd, Apache/Nginx, and cron.
• Perform system upgrades, patching, security hardening, and configuration management.
• Provide Tier 2/3 support for complex infrastructure and enterprise application issues.
• Support and troubleshoot OpenShift/Kubernetes environments and containerized applications.
• Administer Windows Server environments, including Active Directory, DNS, DHCP, Group Policy, and PowerShell.
• Support VMware vSphere/ESXi, including VM deployment, resource management, and troubleshooting.
• Monitor system performance, availability, capacity, and security.
• Collaborate with development, DevOps, infrastructure, and security teams.
• Maintain technical documentation, processes, and standard operating procedures.
• Participate in a weekly on-call rotation and travel to other locations as required.

Required Skills & Qualifications

• Strong hands‑on experience in Linux system administration (RHEL, Ubuntu, and/or CentOS).
• Experience with Linux configuration, patching, troubleshooting, and security.
• Working knowledge of Windows Server administration and core services.
• Familiarity with VMware vSphere/ESXi.
• Knowledge of Apache, Nginx, and related web/application server technologies.
• Understanding of server security and common web application vulnerabilities.
• Strong analytical and independent troubleshooting skills.
• Excellent written and verbal communication skills.
• Ability to collaborate with technical and non-technical stakeholders.
• Willingness to participate in an on-call rotation.

Preferred Qualifications

• Experience with OpenShift, Kubernetes, and/or Docker.
• Experience installing, upgrading, monitoring, and troubleshooting container orchestration environments.
• Familiarity with CI/CD, Git, and DevOps practices.
• Experience with Ansible, Terraform, or other Infrastructure as Code tools.
• Knowledge of Prometheus, Grafana, ELK, or Splunk.
• Certifications such as RHCSA, RHCE, CKA, CKAD, or OpenShift certifications.
• Bachelor’s degree in Computer Science, IT, Engineering, or a related field (preferred; equivalent experience may be considered).

What We’re Looking For

We’re looking for someone who is proactive, security‑conscious, and comfortable handling complex production infrastructure issues. The ideal candidate will bring strong technical expertise, independent problem‑solving skills, and the ability to work effectively across IT, DevOps, development, and security teams.

Interested? We’d love to hear from you!