Senior Systems Administrator

About the position

We are seeking a Senior Systems Administrator to oversee the design, implementation, maintenance, and security of our IT infrastructure. This role is responsible for managing networking, firewalls, servers, virtual machine hosts, user accounts, licenses, and various related IT services. The ideal candidate has a strong background in enterprise-level IT systems, cybersecurity best practices, and troubleshooting complex technical issues.

Responsibilities

• Manage and maintain enterprise networking infrastructure, including routers, switches, VLANs, and VPNs.
• Administer firewalls, intrusion detection/prevention systems (IDS/IPS), and network security policies.
• Ensure network uptime, performance, and redundancy through best practices and monitoring tools.
• Implement and maintain network segmentation, access controls, and encryption protocols.
• Oversee physical and virtual server environments, including Windows Server, Linux, and VMware/Hyper-V.
• Configure, monitor, and maintain domain controllers, DNS, DHCP, and Active Directory.
• Manage storage solutions, including SAN/NAS devices, backups, and disaster recovery plans.
• Optimize performance, capacity planning, and patch management for all servers.
• Administer user accounts, groups, and permissions in Active Directory, Entra, and other identity platforms.
• Manage Microsoft 365 and other enterprise collaboration tools.
• Oversee single sign-on (SSO), multi-factor authentication (MFA), and identity access management (IAM).
• Track and manage software licenses, renewals, and compliance with vendor agreements.
• Maintain documentation of IT assets, software installations, and configurations.
• Provide Tier 3 escalation support for IT issues related to networking, servers, and infrastructure.
• Automate routine tasks using scripting languages (PowerShell, Bash, Python, etc.).
• Develop and maintain IT documentation, standard operating procedures (SOPs), and disaster recovery plans.
• Conduct security audits, vulnerability assessments, and penetration testing.
• Work closely with IT leadership to define infrastructure strategies and long-term roadmaps.
• Coordinate with vendors and service providers for hardware, software, and network services.
• Lead infrastructure projects, upgrades, and migrations with minimal downtime.
• Train and mentor junior IT staff on best practices and system administration.

Requirements

• Bachelor’s degree in computer science, Information Technology, or equivalent experience.
• 5+ years in enterprise IT administration with a focus on networking, servers, and security.

Nice-to-haves

• Cisco Certified Network Associate (CCNA) or higher
• Microsoft Certified: Azure Administrator Associate
• VMware Certified Professional (VCP)
• CompTIA Security+ or CISSP