System and Network Administrator

Job Summary

We are looking for a proactive and detail-oriented System & Network Administrator with 23 years of hands-on experience to manage, maintain, and secure our IT infrastructure. The ideal candidate will have strong expertise across Windows, Linux, and macOS environments, with proven skills in OS and application deployment, Active Directory administration, and firewall management. This role is critical to ensuring the reliability, performance, and security of our organizational systems and network.

Key Responsibilities

Operating System & Application Administration

• Install, configure, and maintain Windows Server (2016/2019/2022), Windows 10/11, Ubuntu/RHEL Linux distributions, and macOS endpoints.
• Deploy, update, and troubleshoot enterprise applications, productivity suites, and internal tools across all platforms.
• Manage OS patch cycles, service packs, and security updates to ensure compliance and system integrity.
• Create and maintain OS images, templates, and automated deployment scripts for rapid provisioning.

Windows Active Directory (AD) Administration

• Administer Active Directory Domain Services (AD DS) including user accounts, groups, organizational units (OUs), and Group Policy Objects (GPOs).
• Manage domain controllers, DNS, DHCP, and certificate services within the AD environment.
• Implement and maintain role-based access controls (RBAC) and enforce security policies via GPOs.
• Handle domain joins for Windows, Linux (using realmd/SSSD), and macOS clients.
• Troubleshoot authentication issues involving Kerberos, LDAP, and NTLM protocols.

Network & Firewall Management

• Configure and manage network firewalls (e.g., Fortinet, Palo Alto, Sophos, pfSense, or equivalent) including rule creation, VPN setup, and traffic monitoring.
• Monitor network performance, troubleshoot connectivity issues, and maintain LAN/WAN/WLAN infrastructure.
• Manage switches, routers, access points, and network segmentation (VLANs).
• Implement and enforce network security policies, intrusion detection/prevention, and access control lists (ACLs).

System Monitoring & Security

• Deploy and maintain endpoint security solutions (antivirus, EDR) across Windows, Linux, and macOS systems.
• Monitor system health, resource utilization, and uptime using monitoring tools (e.g., Nagios, Zabbix, PRTG, or similar).
• Perform periodic security audits, vulnerability assessments, and log analysis.
• Manage backup and disaster recovery solutions to ensure business continuity.

General IT Operations

• Provide Level 2/Level 3 technical support for hardware, software, and network issues.
• Maintain accurate documentation of network topology, system configurations, and standard operating procedures (SOPs).
• Collaborate with cross-functional teams for infrastructure planning, capacity management, and technology upgrades.
• Manage vendor relationships for hardware, software licensing, and support contracts.

Required Qualifications

• 23 years of experience in system administration, network administration, or a related IT infrastructure role.
• Strong working knowledge of Windows Server, Windows Active Directory, Group Policy, DNS, and DHCP.
• Hands-on experience with Linux server administration (Ubuntu, CentOS/RHEL) including command-line operations, package management, and service configuration.
• Experience administering macOS endpoints in an enterprise environment (MDM, FileVault, directory integration).
• Practical experience managing at least one enterprise firewall platform (Fortinet, Palo Alto, Sophos, pfSense, or equivalent).
• Solid understanding of TCP/IP, DNS, DHCP, VPN, VLAN, and common networking protocols.
• Familiarity with endpoint security solutions and security best practices.
• Bachelors degree in Computer Science, Information Technology, or a related field (or equivalent practical experience).

Preferred Qualifications

• Industry certifications such as CompTIA Network+, CompTIA Security+, CCNA, MCSA/MCSE, or equivalent.
• Experience with virtualization platforms (VMware vSphere, Hyper-V, Proxmox).
• Familiarity with scripting and automation (PowerShell, Bash, Python).
• Experience with cloud platforms (AWS, Azure, or GCP) and hybrid environments.
• Knowledge of ITIL processes and IT service management frameworks.
• Experience with containerization tools (Docker, Kubernetes) is a plus.

Key Competencies

Strong analytical and problem-solving skills with the ability to troubleshoot complex multi-platf