Senior Infrastructure Engineer

My Dublin based client is recruiting for a Senior Infrastructure Engineer to join the team on a permanent basis working on a hybrid model. This is a hands-on infrastructure position suited to someone with a strong Microsoft background who is comfortable working across on-premise, cloud, and hybrid environments. You will provide senior-level technical support, manage core infrastructure services, and play an important role in maintaining the security, resilience, and performance of the organisation's technology estate. Key Responsibilities - Manage, maintain, and support Microsoft infrastructure across on-premise and cloud environments. - Administer Windows Server, Active Directory, Group Policy, DNS, and DHCP. - Manage the Microsoft 365 environment, including Exchange Online, SharePoint, Intune, and Entra ID (Azure AD). - Administer and support Microsoft Azure, including hybrid infrastructure environments. - Manage virtualised environments using VMware and/or Hyper-V. - Support and troubleshoot networking technologies, including TCP/IP, VLANs, VPNs, routing, switching, DNS, and DHCP. - Provide advanced L3 support, investigating and resolving complex infrastructure incidents and escalations. - Implement and maintain infrastructure security controls, including MFA, Conditional Access, endpoint security, firewalls, VPNs, and vulnerability remediation. - Manage and maintain backup, disaster recovery, and business continuity solutions and processes. - Develop PowerShell scripts and automation to improve operational efficiency and reduce manual administration. - Monitor infrastructure performance, availability, capacity, and security. - Maintain accurate technical documentation, procedures, and infrastructure records. - Work closely with internal stakeholders, third-party suppliers, and other technical teams on infrastructure projects and improvements. Key Experience The successful candidate will have: - 5+ years' experience in a Senior Systems Administrator, Infrastructure Engineer, or similar infrastructure-focused position. - Strong hands-on experience with Windows Server and Microsoft infrastructure technologies. - Strong knowledge of Active Directory, Group Policy, DNS, and DHCP. - Strong Microsoft 365 administration experience covering Exchange Online, SharePoint, Intune, and Entra ID. - Strong Microsoft Azure administration experience, ideally within hybrid environments. - Experience with VMware and/or Hyper-V virtualisation. - Strong networking knowledge across TCP/IP, DNS, DHCP, VLANs, VPNs, routing, and switching. - Experience managing enterprise infrastructure spanning on-premise and cloud environments. - Strong understanding of infrastructure and security best practices, including MFA, Conditional Access, vulnerability remediation, endpoint security, firewalls, and VPNs. - Practical experience with backup, disaster recovery, and business continuity. - Hands-on PowerShell scripting and automation experience. - Demonstrable experience handling complex L3 escalations and infrastructure troubleshooting. - Strong technical documentation and stakeholder management skills. Desirable Experience The following would be advantageous: - Relevant Microsoft Azure certifications. - Experience with Docker and Kubernetes. - Experience with infrastructure monitoring platforms such as SCOM, Nagios, Zabbix, Prometheus, or Azure Monitor.