Senior Systems & Microsoft 365 Administrator (On-Call)

Arnold Oil Company; Austin (TX); On-site; USD 85,000 - 110,000; Full time

Job summary

Arnold Oil Company is seeking a Systems Administrator II to ensure stability, performance, and security of our IT infrastructure, including desktop, server, network, and cloud environments. You will deliver reliable services to end users and support Microsoft 365 tools and security controls.

The role requires 5+ years of Windows support experience, strong AD/GP knowledge, and hands-on networking skills. On-call, off-hours support and regional travel may be required as part of maintaining a

Qualifications

• Minimum 5 years of experience supporting Windows clients in a corporate environment.
• Deep knowledge of Windows OS, Active Directory, and Group Policy.
• Strong PC hardware expertise and ability to resolve complex hardware/software issues.
• Solid understanding of TCP/IP networking and Windows domain environments.
• Proven experience administering Microsoft 365 (Exchange Online, Teams, SharePoint, Intune, etc.).
• Experience with Microsoft 365 identity and security controls (Entra ID, MFA, Conditional Access, endpoint compliance).
• Experience with VPN client installation and troubleshooting.
• Ability to detect, mitigate, and recover from malware and security incidents.
• Excellent written and oral communication with focus on documentation.

Responsibilities

• Install, configure, upgrade, and troubleshoot hardware, software, and operating systems.
• Manage routers, switches, firewalls, and VPN solutions (site-to-site and client-based).
• Provide Tier 2/3 support for end-user applications and remote laptop users.
• Administer and support Microsoft 365, including Exchange Online, Teams, SharePoint, OneDrive, Intune and security features.
• Maintain system and software license inventories.
• Deploy, configure, and manage VoIP infrastructure.
• Perform racking, installation, and cabling as needed.
• Configure and troubleshoot wireless networks and related technologies.
• Develop and maintain network documentation, topology diagrams, and SOPs.
• Collaborate with security teams to align with identity, endpoint security, and data protection best practices.

Skills

Windows OS

Active Directory

Group Policy

TCP/IP networking

Microsoft 365 administration

Entra ID / MFA / CA

VPN troubleshooting

Security incident response

Education

High School Diploma or GED

College Degree Preferred

Tools

Microsoft 365

Exchange Online

Teams

SharePoint

OneDrive

Intune

Job description

Arnold Oil Company is seeking a Systems Administrator II to ensure stability, performance, and security of our IT infrastructure, including desktop, server, network, and cloud environments. You will deliver reliable services to end users and support Microsoft 365 tools and security controls.

The role requires 5+ years of Windows support experience, strong AD/GP knowledge, and hands-on networking skills. On-call, off-hours support and regional travel may be required as part of maintaining a