Senior Network & Systems Administrator

Job Description

Job Overview

We are seeking an experienced Senior Network & Systems Administrator to manage, maintain, and optimize our enterprise IT

infrastructure, including networks, servers, virtualization platforms, and data center operations. The role requires strong hands-

on technical expertise, independent troubleshooting, and a proactive approach to infrastructure reliability, security, and business

continuity. The successful candidate will work closely with NOC, IT support, security, and other internal teams, as well as external

service providers.

Network Administration

• Configure, administer, monitor, and troubleshoot enterprise LAN/WAN, VLANs, IP addressing, routing, switching, and VPN
• connectivity.
• Manage enterprise firewalls, security policies, NAT, access controls, and site-to-site connectivity.
• Support routing protocols such as BGP and OSPF, along with network redundancy and high-availability configurations.
• Monitor network performance, investigate connectivity and latency issues, and maintain reliable network services.
• Coordinate with ISPs and network service providers on provisioning, outages, troubleshooting, and service availability.

Systems & Virtualization

• Administer Linux and Windows Server environments, including installation, configuration, maintenance, upgrades, and
• troubleshooting.
• Manage virtualization platforms such as VMware vSphere, ESXi, and vCenter, including VM provisioning, resource allocation,
• templates, and lifecycle operations.
• Maintain virtual infrastructure availability and performance, including VMware HA/DRS and related resilience features where
• deployed.
• Support core infrastructure services such as DNS, DHCP, Active Directory, Group Policy, and related identity services.
• Perform OS patching, firmware updates, capacity checks, and performance optimization.

Data Center Operations

• Support daily data center operations across compute, storage, networking, and associated facilities coordination.
• Monitor storage capacity, performance, availability, and redundancy; assist with expansion and lifecycle planning.
• Maintain infrastructure redundancy and resilience, including N+1/N+N designs where applicable.
• Coordinate hardware installation, replacement, firmware upgrades, preventive maintenance, and planned maintenance
• windows.
• Maintain accurate infrastructure inventories, rack layouts, network diagrams, and asset records.

Monitoring, Backup & Disaster Recovery

• Monitor infrastructure availability, performance, and capacity using platforms such as Zabbix, Grafana, Checkmk, or equivalent
• tools.
• Administer backup operations, investigate failures, verify backup integrity, and maintain backup schedules and retention.
• Support disaster recovery planning, replication, recovery procedures, and periodic recovery/DR testing.
• Maintain alerting, dashboards, operational reports, and infrastructure health checks.
• Identify recurring incidents and capacity trends, and implement preventive actions to improve service reliability.

Security & Compliance

• Apply infrastructure security practices including least privilege, MFA, access control, network segmentation, and system
• hardening.
• Perform security patching, vulnerability remediation, configuration reviews, and periodic access reviews.
• Support security incident investigation, log analysis, containment, and remediation activities.
• Maintain technical evidence and documentation for audits and applicable compliance frameworks, including ISO 27001.
• Ensure infrastructure configurations and operations follow organizational security policies and standards.

Incident, Change & Operational Management

• Independently diagnose and resolve complex network, system, virtualization, and infrastructure incidents.
• Participate in incident response, escalation, root cause analysis (RCA), and post-incident reviews.
• Follow change management procedures, including impact assessment, approvals, maintenance windows, validation, and
• rollback planning.
• Develop and maintain SOPs, runbooks, troubleshooting guides, recovery procedures, and technical documentation.
• Coordinate with NOC, IT support, security, and other technical teams to support timely incident resolution and effective shift
• handovers.
• Provide technical guidance to junior administrators and participate in on-call support and scheduled maintenance as required.

Requirements

• Minimum 5 years of relevant hands-on experience in network and systems administration, preferably in an enterprise or data
• center environment.
• Bachelor’s degree in Information Technology, Computer Engineering, Computer Science, or a related field, or equivalent
• practical experience.
• Strong understanding of TCP/IP, subnetting, VLANs, routing, switching, VPNs, and firewall administration.
• Practical experience administering Linux and Windows Server environments.
• Hands-on experience with VMware vSphere, ESXi, vCenter, or comparable virtualization platforms.
• Experience with backup solutions, infrastructure monitoring, patch management, and disaster recovery operations.
• Understanding of high availability, redundancy, storage, and business continuity concepts.
• Knowledge of infrastructure security, access management, system hardening, and vulnerability remediation.
• Strong troubleshooting, analytical, documentation, and communication skills.
• Ability to work independently, take ownership of technical issues, and collaborate across teams.

Preferred Qualifications

• Certifications such as CCNA, CCNP, RHCSA, Microsoft Windows Server, VCP, or equivalent.
• Experience with enterprise firewalls such as Fortinet, Palo Alto, or equivalent.
• Practical exposure to BGP, OSPF, multi-ISP connectivity, and network high availability.
• Familiarity with Zabbix, Grafana, Checkmk, or equivalent monitoring platforms.
• Basic scripting or automation experience using Bash, PowerShell, or Python.
• Exposure to AWS, Microsoft Azure, or hybrid cloud environments.
• Experience supporting ISO 27001 or other information security/service management frameworks.

What We’re Looking For

• A technically strong, hands-on administrator who can manage infrastructure with limited day-to-day supervision.
• A methodical troubleshooter who takes ownership from initial diagnosis through resolution and documentation.
• A proactive team member who values security, reliability, clear communication, and continuous improvement.
• Someone willing to share knowledge, support junior colleagues, and contribute to a collaborative operations team.