System Administrator III

Calista Corporation • Huntsville, AL

1d • Onsite

About The Position

The System Administrator III maintains and secures IT infrastructure supporting a collateral storage facility on a closed, isolated network. The role administers Windows and Linux systems, configures secure network services, manages backup and recovery processes, enforces access controls, and implements security hardening measures. The work takes place in an indoor, secure, access-controlled facility, with no shift or on-call work required. There are no supervisory responsibilities, though the position may mentor junior staff as needed.

Requirements

• Bachelor's degree in IT, computer science, or a related field, or equivalent experience.
• At least 3 years of system administration experience.
• Experience with Linux and Windows server environments.
• Active DoW Secret clearance.
• Proficiency with Linux and Windows administration.
• Knowledge of networking fundamentals, including DNS, DHCP, routing, and firewalls.
• Understanding of secure configuration standards and vulnerability remediation.
• Familiarity with backup systems and disaster recovery.
• Ability to script using PowerShell or Bash.
• Strong analytical and documentation skills.

Nice To Haves

• Certifications such as Security+, Network+, RHCSA, or CCNA.

Responsibilities

• Administer and maintain Windows and Linux servers in a closed network environment.
• Manage user accounts, access permissions, and authentication controls.
• Perform patching, system hardening, and secure configuration of operating systems and applications.
• Configure and monitor firewalls, DNS, DHCP, and connectivity services.
• Implement and test backup schedules and disaster recovery processes.
• Maintain documentation, configuration baselines, and inventories.
• Monitor logs and alerts for anomalies and troubleshoot issues.
• Support hardware installation and maintenance within the facility.
• Mentor junior staff as required.

What This Job Offers

• Job Type: Full-time
• Career Level: Mid Level