We are seeking a skilled Senior IT Operation Engineer to manage, secure, and optimize our IT infrastructure across servers, networks, storage, virtualization, and unified communications. This role involves hands-on administration of Microsoft and Linux environments, enterprise networking, firewalls, and VoIP systems, ensuring high availability, performance, and security of all IT services.ResponsibilitiesInstall, configure, and maintain Microsoft Exchange, Active Directory, DNS, DHCP, and Domain Controllers, including GPOs, authentication, and email service connectivity and security.Manage network infrastructure using MikroTik and Cisco routing and switching equipment, ensuring reliable LAN/WAN connectivity, VLAN segmentation, and efficient traffic flow.Configure and administer FortiGate firewalls, including VPN, intrusion prevention and HA setups.Oversee virtualization platforms such as VMware ESXi, provision VMs, manage SAN/NAS storage, and implement backup and disaster recovery plans.Administer Microsoft and Linux servers, managing core services, applications, databases, updates, patches, and performance optimization.Operate and maintain Issabel VoIP services, including SIP trunk configuration, call routing, and troubleshooting quality issues.Oversee and maintain multiple secure connections between company branches, including VPN and dedicated links, ensuring reliable communication and data transfer.Manage CCTV systems and related network services across branches, ensuring high availability, security, and integration with monitoring tools.Apply security hardening and access controls across systems, monitor logs, ensure compliance, and proactively address vulnerabilities.Monitor and analyze system and network health, perform capacity planning, maintain accurate documentation, and provide Tier-3 technical support.QualificationsBachelor’s degree in Computer Science, Information Technology, or equivalent experience.Minimum 5 years’ experience in enterprise IT infrastructure administration.Expertise in Microsoft Server technologies, networking, virtualization, storage, and VoIP.Strong troubleshooting skills and ability to work under pressure.Strong communication and interpersonal skills, with the ability to work effectively with technical and non-technical teams.Preferred certifications: Microsoft (Exchange, Windows Server), Cisco CCNA/CCNP, VMware VCP, Linux LPIC2.