Linux System Admin Jobs in Chicago, IL (NOW HIRING)

Summary:

The Associate Principal, Strong at least 10 years Deep Linux administration skills, Linux Administrator is responsible for managing and maintaining enterprise Linux server environments through hands-on daily operational activities. This role ensures the stability, performance, security, and availability of Linux infrastructure across on-premises and cloud environments. The position requires strong operational expertise, a proactive approach to system health, and the ability to work across US Day and night shifts to provide continuous 24/7 coverage for critical infrastructure.

Primary Duties and Responsibilities:

To perform this job successfully, an individual must be able to perform each primary duty satisfactorily.

• Monitor, manage, and maintain enterprise Linux server environments (RHEL, CentOS, Ubuntu, Amazon Linux) on a day-to-day basis across on-premises and cloud infrastructure
• Perform routine system health checks including CPU, memory, disk utilization, and process monitoring across all Linux servers
• Respond to system alerts, service failures, and performance degradation in a timely manner; triage and resolve incidents within defined SLA windows
• Manage user accounts, groups, permissions, and SSH key administration across Linux systems
• Administer cron jobs, scheduled tasks, and system services (systemd, init) to ensure uninterrupted operations
• Perform log analysis and monitoring using tools such as journald, rsyslog, ELK Stack, Splunk, or CloudWatch to identify anomalies and recurring issues
• Execute day-to-day storage operations including LVM management, filesystem extension, NFS mount management, and disk space remediation
• Troubleshoot OS-level issues including boot failures, kernel panics, network connectivity problems, and service disruptions
• Coordinate and execute scheduled maintenance activities including reboots, service restarts, and configuration updates during approved change windows
• Apply security patches, kernel updates, and bug fixes to Linux servers in alignment with the enterprise patching schedule using Red Hat Satellite and Ansible Automation Platform (AAP)
• Validate patch deployments in non-production environments prior to production rollouts and perform post-patch validation checks to confirm system stability and service availability
• Support emergency and zero-day vulnerability patching as directed by the security team
• Enforce CIS benchmark standards and security baselines on Linux systems; remediate non-compliant configurations
• Perform periodic security scans using OpenSCAP, Lynis, or Nessus and document findings for remediation tracking
• Actively manage incidents, service requests, and change records using ServiceNow, ensuring timely updates, proper categorization, and SLA compliance
• Serve as an escalation point for Tier 1/Tier 2 Linux issues during assigned shift
• Participate in root cause analysis (RCA) and post-incident reviews for major Linux-related outages
• Execute approved change requests during maintenance windows including patching, configuration changes, and server builds
• Maintain clear and accurate shift handover notes to ensure operational continuity across US Day and night shifts
• Provision new Linux servers (physical, virtual, and cloud) following approved build standards and golden image baselines
• Configure servers post-build including network settings, storage mounts, security hardening, and application-level prerequisites
• Support AMI (Amazon Machine Image) updates and golden image refreshes for AWS EC2 instances
• Execute Ansible playbooks for configuration management, compliance enforcement, and routine operational tasks
• Proactively monitor infrastructure dashboards (CloudWatch & Splunk) and act on alerts
• Identify performance bottlenecks and work with senior engineers to implement optimizations
• Perform capacity monitoring and report disk, CPU, and memory trends as inputs to capacity planning
• Work assigned US Day shift (EST/CST 8 AM 6 PM)
• Act as the primary Linux operations contact during assigned shift for incident response, change execution, and escalation management
• Follow runbooks and standard operating procedures (SOPs) for all operational activities and maintain shift logs with current server and service status
• Create and maintain runbooks, SOPs, knowledge base articles, and operational checklists in Confluence
• Track tasks, incidents, and project work in JIRA with accurate and timely status updates
• Collaborate with network, storage, security, and application teams to resolve cross-functional issues
• Participate in team meetings, sprint reviews, and operational planning sessions

Qualifications:

The requirements listed are representative of the knowledge, skill, and/or ability required. Reasonable accommodations may be made to enable individuals with disabilities to perform the primary functions.

• 10 + years of progressive hands-on experience in Linux/Unix system administration in an enterprise environment
• Demonstrated experience managing Linux servers in production environments at scale
• Strong hands-on experience with Ansible Automation Platform (AAP) including playbook execution and operational automation
• Working experience with Red Hat Satellite for patch deployment and content lifecycle management
• Hands-on experience with AWS Linux EC2 instances including basic instance operations, snapshots, and security group management
• Demonstrated experience implementing and maintaining CIS benchmarks and security baselines across enterprise Linux systems
• Extensive experience with enterprise Linux patching programs including change management, patch validation, and emergency patching procedures
• Working experience with ITSM platforms such as ServiceNow for incident, problem, and change management
• Proficiency with collaboration and project management tools including JIRA and Confluence
• Excellent problem-solving abilities and analytical thinking skills
• Strong written and verbal communication skills with ability to produce clear shift handover notes and operational documentation
• Ability to multitask and prioritize effectively in a fast-paced operational environment