Senior Linux Systems Engineer – Remote Secure Infrastructure

Lumen; Phoenix (AZ); Remote; USD 83,000 - 122,000; Full time

Benefits offered by this job

Health benefits

Job summary

Lumen is the trusted network for the AI‑powered world, delivering secure, high‑performance connectivity across cloud, edge, and AI workloads. This Senior Linux Systems Administrator role designs and builds Linux-based infrastructure for a classified federal program, with emphasis on VMware/KVM virtualization, authentication services, vulnerability management, and automation.

Remote, nationwide U.S. location.

Qualifications

• Six or more years of experience in Linux systems, infrastructure, network, security, or platform administration.
• Advanced administration experience with Ubuntu and RHEL.
• Strong command-line proficiency, including Bash scripting and CLI-based troubleshooting.
• Demonstrated experience designing and building production infrastructure from the ground up.
• Hands-on experience administering VMware ESXi, vCenter, and vSphere.
• Experience with KVM or comparable Linux-based virtualization technology.
• Experience administering Nessus or a comparable vulnerability-management platform.
• Experience managing SSL/TLS certificates and public-key infrastructure concepts.
• Strong knowledge of LDAP, LDAPS, and Active Directory integration.
• Working knowledge of TCP/IP, routing, DNS, NTP, firewalls, switching, ports, and network troubleshooting.
• Experience with Ansible and infrastructure automation.
• Working knowledge of Python and Git.
• Experience supporting monitoring and logging tools such as Zabbix and Elastic Stack.
• Ability to troubleshoot across operating systems, virtualization, authentication, applications, and network infrastructure.
• Active TS clearance with current SSBI/T5R investigation and CI polygraph, if those remain mandatory for the program.

Responsibilities

• Design and build secure Linux infrastructure from initial requirements through production implementation and operational handoff.
• Install, configure, administer, patch, harden, and troubleshoot Ubuntu and Red Hat Enterprise Linux systems.
• Perform advanced command-line administration using Bash and standard Linux diagnostic and management utilities.
• Administer VMware ESXi, vCenter, and vSphere environments, including hosts, virtual machines, templates, storage, virtual networking, certificates, resource allocation, backups, and recovery.
• Build and maintain KVM-based virtualization environments and support evaluation or migration between virtualization platforms.
• Provision physical and virtual servers and integrate them with network, storage, DNS, NTP, directory, monitoring, backup, and security services.
• Install, configure, maintain, and troubleshoot LDAP and Active Directory integrations, including LDAP, LDAPS, bind accounts, directory searches, groups, permissions, and certificate trust.
• Manage the SSL/TLS certificate lifecycle, including private keys, certificate requests, SANs, certificate installation, chain validation, renewal, expiration tracking, and trust troubleshooting.
• Administer Nessus vulnerability-scanning infrastructure, maintain scan configurations and schedules, analyze findings, and support remediation and validation.
• Maintain monitoring and logging platforms such as Zabbix and Elastic Stack.
• Troubleshoot network connectivity involving routing, DNS, ports, protocols, firewalls, switches, NAT, access controls, and application-to-system communication.
• Create and maintain automation using Ansible, Bash, and Python.
• Use Git and GitLab CI/CD to manage infrastructure code, scripts, configurations, and deployment workflows.
• Read, troubleshoot, and make limited modifications to applications or services developed with frameworks such as Flask or Django.
• Support REST API integration between applications, infrastructure platforms, and network or security elements.
• Develop and maintain accurate build guides, system diagrams, configuration records, operational procedures, backup procedures, and recovery documentation.
• Participate in system upgrades, incident response, problem management, capacity planning, and lifecycle management.
• This position requires between 5-20% Travel to accommodate customer meetings and servicing hardware on-site

Skills

Linux

Bash

Python

Ansible

Git

GitLab

Zabbix

Elastic Stack

REST APIs

AD integration

TLS/SSL

Nessus

LDAP

VMware ESXi

vCenter/vSphere

KVM

Tools

Ubuntu

RHEL

Nessus

VMware ESXi

vCenter

vSphere

Ansible

Python

GitLab CI/CD

Zabbix

Elastic Stack

Job description

Lumen is the trusted network for the AI‑powered world, delivering secure, high‑performance connectivity across cloud, edge, and AI workloads. This Senior Linux Systems Administrator role designs and builds Linux-based infrastructure for a classified federal program, with emphasis on VMware/KVM virtualization, authentication services, vulnerability management, and automation.

Remote, nationwide U.S. location.