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# Systems Administrator, Senior

- **Company:** Sentinel Real Estate Corporation
- **Location:** Green Bay, WI, United States
- **Experience:** Expert
- **Contract:** Permanent contract
- **Skills:** Microsoft Windows, Active Directory, Application Firewall, Business Systems, Cisco IOS, Configuration Management, Computer Networks, Dynamic Host Configuration Protocol, Domain Name System (DNS), Hyper-V, Information Technology Operations, Networking Hardware, Microsoft Software, System Center Configuration Manager, Windows Servers, Network Architecture, Routing, Network Administration, Remote Access Technology, Microsoft SharePoint, TCP/IP, Software Vulnerability Management, SSL Certificate Management, System Availability, Patch Management
- **Published:** November 13, 2026
- **Apply:** https://www.careerbuilder.com/job-details/systems-administrator-senior-green-bay-wi--3f58702b-d0cd-4f4e-a770-58bbb0c3f81d

## About the Role

Systems Administration/Management, Business Solutions, High Availability, Problem Solving Skills, Organizational Skills, Systems Administration/Management, Network Administration/Management, Technical Support, Detail Oriented, Software Upgrades, * Minimum of 7 years of experience in a network, systems administration, or infrastructure support role.

 * Advanced experience designing, implementing, and troubleshooting Microsoft 365 environments.
 * Strong expertise in Active Directory, Group Policy, Exchange, SharePoint, Hyper-V, and Microsoft Configuration Manager (SCCM/MECM).
 * Hands-on experience with Windows Server administration, patch management, and system migrations.
 * Experience with enterprise firewall administration, certificate management, and vulnerability remediation.
 * Strong understanding of networking concepts, including routing, switching, TCP/IP, DNS, DHCP, and VPN technologies.
 * Experience performing Cisco IOS XE upgrades and network device maintenance.
 * Knowledge of cybersecurity best practices, security monitoring, and incident response procedures.
 * Excellent troubleshooting, communication, and customer service skills.
 * Legally authorized to work in the US without sponsorship
 * Must demonstrate a "can-do" attitude
 * We focus on candidates that display our "ACE" factor - Attitude, Compassion, and Enthusiasm to deliver quality solutions with exceptional customer service.

We focus on candidates that display our "ACE" factor - Attitude, Compassion, and Enthusiasm to deliver quality solutions with exceptional customer service.

## Description

We are seeking a reliable and detail-oriented System Administrator to maintain, upgrade, and manage our software, hardware, and network infrastructure for our client. In this role, you will ensure high availability and security across all business systems while providing escalated technical support to end-users. The ideal candidate is a proactive problem-solver with strong organizational skills and a solid foundation in IT operations. This is a 3-5 month contract position reporting onsite at our client location in Green Bay, WI.