IT Infrastructure Administrator

Overview

We are seeking a highly motivated Infrastructure Administrator to join our Infrastructure team. The ideal candidate will have experience supporting Microsoft technologies, virtualization platforms, enterprise backup solutions, and networking technologies.

Based in our San Jose office, this hybrid role combines systems administration and network administration responsibilities, supporting both on‑premises and cloud infrastructure. Working closely with senior infrastructure staff, this role is responsible for maintaining a secure, reliable, and scalable IT environment while troubleshooting technical issues, supporting infrastructure projects, and helping improve operational efficiency.

The ideal candidate is a well rounded Infrastructure professional who enjoys working across multiple technologies rather than specializing exclusively in systems or networking. This position is intended for a mid level engineer with growth potential into a senior role, with opportunities to expand technical expertise and assume increased responsibility for infrastructure systems and projects over time. Success in this role requires strong troubleshooting skills, a collaborative mindset, and a willingness to continuously learn and adapt to evolving technologies.

• Administer and maintain Microsoft Active Directory, Group Policy, DNS, DFS, and File Services.
• Administer Microsoft 365 services including Exchange Online, Entra  (Azure AD), Enterprise Applications, Conditional Access, and Single Sign On (SSO).
• Support identity-based integrations, including OAuth and enterprise application configurations.
• Perform Windows Server administration, including installation, configuration, patching, maintenance, and troubleshooting.
• Support VMware vSphere, VxRail, and virtual server environments.
• Assist with virtual machine provisioning, server lifecycle management, and infrastructure upgrades.
• Monitor and maintain enterprise backup and disaster recovery solutions, including Cohesity, AvePoint, and Zerto.
• Manage internal Certificate Authority (PKI) and external SSL certificates.
• Support enterprise email services, including Exchange Online, Mimecast, email routing, SPF, DKIM, DMARC, and SaaS integrations.
• Support Microsoft Defender for Office 365 (MDO), Abnormal Security, and email security platforms.
• Perform server hardware maintenance, upgrades, and lifecycle replacements.
• Maintain accurate infrastructure documentation, including server inventories, network diagrams, configuration standards, and operational procedures.

• Support the administration and maintenance of enterprise LAN, WAN, wireless, and SD‑WAN environments.
• Configure and troubleshoot Cisco and Meraki switches.
• Support administration of Meraki firewalls and security appliances.
• Support Azure networking components and hybrid connectivity.
• Monitor WAN circuits and coordinate with Internet Service Providers.
• Support Cisco Umbrella/OpenDNS and DNS services.
• Troubleshoot wired and wireless network connectivity issues.
• Maintain network configurations, VLANs, and switch documentation.
• Monitor and maintain UPS systems and supporting infrastructure equipment.
• Support the administration and troubleshooting of the Cato SASE platform, including SD‑WAN, remote access connectivity, traffic steering, and network segmentation.
• Assist with traffic flow validation and hybrid network troubleshooting.

• Monitor infrastructure health, performance, and availability using Logic Monitor and other monitoring tools.
• Respond to infrastructure alerts, incidents, and service requests.
• Troubleshoot server, storage, virtualization, networking, Microsoft 365, and cloud‑related issues.
• Coordinate with vendors to resolve hardware, software, and service‑related incidents.
• Ensure backup jobs, replication, and disaster recovery processes complete successfully.
• Perform proactive system health checks and preventative maintenance.
• Perform root cause analysis for recurring issues and recommend long‑term corrective actions.

• Support Microsoft security best practices across server, cloud, and network…