Linux L3 System Administrator

Job Description Linux L3 System Administrator

Job Summary

The Linux L3 System Administrator is responsible for advanced administration, architecture, automation, and support of enterprise Linux environments across on-premises and cloud platforms. The role focuses on infrastructure automation using Terraform, container platform administration, cloud provisioning, performance optimization, and providing technical leadership for complex incidents and infrastructure transformation initiatives.

Key Responsibilities

• Provide L3-level support for Linux operating systems including RHEL, Oracle Linux, Rocky Linux, and CentOS.
• Act as the final escalation point for complex operating system, performance, and infrastructure issues.
• Design, deploy, and maintain highly available Linux platforms in physical, virtual, and cloud environments.
• Develop and manage Infrastructure as Code (IaC) solutions using Terraform.
• Create, maintain, and optimize Terraform modules, workspaces, and state management processes.
• Automate infrastructure provisioning across Azure, AWS, OCI, or hybrid cloud environments.
• Administer and support Kubernetes/OpenShift container platforms.
• Deploy, monitor, troubleshoot, and upgrade Kubernetes clusters and worker nodes.
• Implement automation using Ansible, Terraform, Shell scripting, and Python.
• Manage Linux storage technologies including LVM, Multipathing, SAN/NAS integrations, and enterprise storage solutions.
• Lead OS patching, upgrades, lifecycle management, and vulnerability remediation activities.
• Drive security hardening and compliance initiatives across Linux and cloud environments.
• Analyze system performance and perform proactive capacity planning and tuning.
• Support VMware and enterprise virtualization platforms.
• Collaborate with application, database, network, cloud, and security teams on solution design and implementation.
• Participate in major incident management, root cause analysis, and problem management activities.
• Mentor L1/L2 engineers and contribute to documentation, SOPs, and best practices.
• Participate in 24x7 on-call support and planned maintenance activities.

Required Skills & Experience

• 8–10+ years of enterprise Linux administration experience.

• Strong expertise in:

• Red Hat Enterprise Linux (RHEL)

• Oracle Linux

• Rocky Linux

• Hands-on experience with Terraform for infrastructure provisioning and lifecycle management.

• Experience creating reusable Terraform modules and managing remote state backends.

• Strong knowledge of Infrastructure as Code (IaC) principles and DevOps practices.

• Experience with Kubernetes and/or OpenShift administration.

• Proficiency with Ansible automation.

• Strong Shell scripting (Bash) and Python skills.

• Experience with:

• LVM

• Multipathing (DM-Multipath/PowerPath)

• SAN/NAS Storage

• Enterprise Backup Solutions

• Advanced Linux troubleshooting and performance tuning experience.

• Strong understanding of networking concepts:

• DNS

• TCP/IP

• VLANs

• Bonding

• Load Balancing

• Experience with ServiceNow or similar ITSM tools.

• Experience working in mission-critical 24x7 production environments.

Preferred Qualifications

• RHCE / RHCA certification.
• HashiCorp Terraform Associate certification.
• Certified Kubernetes Administrator (CKA).
• Red Hat OpenShift Certification.
• Azure Administrator, AWS SysOps, or OCI certifications.
• Experience with GitHub, GitLab, Jenkins, or Azure DevOps pipelines.
• Exposure to GitOps tools such as ArgoCD or FluxCD.
• Experience supporting cloud-native and microservices-based environments.
• ITIL Foundation certification.

Professional Attributes

• Strong ownership mindset and decisionmaking capabilities
• Ability to handle highpressure, businesscritical incidents
• Excellent communication and stakeholder management skills
• Passion for automation, standardization, and continuous improvement