Systems Administrator

COMPANY OVERVIEW ThreatLocker® is a global cybersecurity company providing enterprise-level endpoint protection solutions that help organizations secure their servers, workstations, and critical infrastructure. The ThreatLocker® platform includes Application Allowlisting, Ringfencing™, Storage Control, Elevation Control, Endpoint Network Control, Configuration Management, and Operational Alert solutions, enabling organizations to adopt a Zero Trust approach that blocks malicious activity before it can execute. As part of our continued growth across Europe, we are seeking a Systems Administrator to join our team in Dublin, Ireland. POSITION OVERVIEW ThreatLocker is seeking an experienced Systems Administrator to join our IT Infrastructure team. This is an in-office position based in Dublin and is responsible for maintaining, securing, and improving the company's internal infrastructure. The successful candidate will have extensive experience administering Microsoft Windows Server environments, Hyper-V virtualization, Microsoft SQL Server, Active Directory, and enterprise networking. Experience supporting Linux servers and modern DevOps technologies is desirable but not essential. This role requires an individual who enjoys solving complex technical problems, can work independently, and is committed to maintaining a highly available, secure, and scalable infrastructure. KEY RESPONSIBILITIES The Systems Administrator will be responsible for, but not limited to: • Administering and maintaining Windows Server environments. • Managing Active Directory, Group Policy, DNS, DHCP, and related Microsoft infrastructure services. • Administering and maintaining Hyper-V virtualization infrastructure. • Installing, configuring, maintaining, and troubleshooting Microsoft SQL Server environments. • Managing enterprise storage, backup, and disaster recovery solutions. • Monitoring infrastructure performance, availability, and capacity. • Installing, configuring, and maintaining network infrastructure, including switches, firewalls, wireless networks, VLANs, VPNs, and routing. • Troubleshooting server, storage, networking, virtualization, and operating system issues. • Planning and implementing infrastructure upgrades and system improvements. • Applying operating system updates, firmware updates, and security patches. • Implementing and maintaining cybersecurity best practices across the server and network environment. • Creating and maintaining technical documentation, network diagrams, and standard operating procedures. • Supporting office infrastructure and assisting with IT projects across multiple international locations. • Working closely with internal engineering, development, and security teams to ensure reliable and secure infrastructure. • Learn ThreatLocker products fully. • On-call / After hour calls required REQUIRED QUALIFICATIONS • Minimum of 3 years' experience as a Systems Administrator or Systems Engineer. • Extensive experience administering Microsoft Windows Server. • Strong knowledge of Active Directory, Group Policy, DNS, DHCP, and Windows networking. • Extensive experience with Microsoft Hyper-V. • Strong experience administering Microsoft SQL Server. • Experience managing enterprise networking equipment, including switches, firewalls, VPNs, VLANs, and routing. • Strong understanding of storage technologies, backup solutions, and disaster recovery. • Experience troubleshooting complex server and infrastructure issues. • Excellent problem-solving and analytical skills. • Ability to create and maintain technical documentation. • Strong verbal and written communication skills. • Ability to prioritise workload and work effectively in a fast-paced environment. DESIRABLE QUALIFICATIONS • Experience administering Linux servers (Ubuntu, Debian, Red Hat, or similar). • Experience with Microsoft Azure or AWS. • Experience with PowerShell scripting and automation. • Experience with Docker or Kubernetes. • Familiarity with CI/CD pipelines and DevOps practices. • Experience with Infrastructure as Code tools such as Terraform or Ansible. • Microsoft, Azure, VMware, Linux, or networking certifications. PERSONAL ATTRIBUTES The ideal candidate will: • Be highly organised and detail-oriented. • Take ownership of technical issues through to resolution. • Be proactive in identifying opportunities for improvement. • Work well independently and as part of a team. • Communicate effectively with both technical and non-technical colleagues. • Demonstrate a strong customer-service mindset. • Be eager to learn new technologies and continually develop their technical skills. WORKING CONDITIONS The duties described are representative of those encountered while performing the essential functions of this role. Reasonable accommodations will be considered where appropriate. • This is a full-time, in-office position based in Dublin, Ireland. • Occasional travel to other ThreatLocker offices may be required. • The role involves prolonged periods of sitting and computer work. • Occasional lifting and installation of IT equipment weighing up to 25 kg. • May occasionally require work outside normal business hours to support maintenance of windows or critical incidents. A background check and drug/substance screening are required after a conditional offer. Employment will proceed only upon receiving clear results from both. ThreatLocker also conducts randomized drug and substance testing approximately every 60 days, in line with the same screening standards.