We are seeking an experienced Senior IT Systems Administrator to join our IT Operations function in Dublin. This is a senior, hands‑on role focused on the design, implementation, and support of secure, enterprise‑scale infrastructure, with a strong emphasis on cyber security initiatives.
Acting as a key interface between Cyber Security project teams and IT Operations, you will play a central role in delivering security‑driven infrastructure enhancements, ensuring resilience, compliance, and operational excellence across a 24x7 critical environment.
Key Responsibilities
Lead infrastructure workstreams across cyber security projects within a high‑availability operational environment
Design, build, and maintain secure, scalable Microsoft‑based infrastructure solutions
Drive implementation of security best practices, including system hardening and vulnerability remediation
Own patch management processes and ensure ongoing compliance with security standards
Develop and maintain documentation to support internal and external audit requirements
Execute and oversee system administration activities to maintain optimal system health
Design and implement high‑availability and disaster recovery solutions
Collaborate with application and network teams to ensure performance, resilience, and secure data flows
Provide advanced troubleshooting support for escalated technical issues
Monitor infrastructure and security performance against defined SLAs
Contribute to continuous improvement of operational processes and procedures
Mentor junior team members and support capability development within the team
Required Experience & Skills
5+ years’ experience in a senior systems administration role within a large enterprise environment
Strong expertise in Microsoft technologies and enterprise infrastructure design
Advanced knowledge of:
Windows Server (2019/2022/2025)
Active Directory and Group Policy
Solid understanding of networking concepts and protocols
Experience with backup and recovery solutions (NetBackup advantageous)
Familiarity with ITIL‑based service management environments
Strong analytical and problem‑solving capabilities
Ability to work both independently and collaboratively within a team
Excellent communication and documentation skills
Experience with virtualization platforms (e.g. VMware) and storage technologies
Exposure to Linux environments (RedHat/OEL)
Automation experience using tools such as Python, Ansible, or REST APIs
Certifications & Qualifications
Relevant third‑level qualification in IT or equivalent practical experience
Industry certifications such as MCSA, MCP, or CCNA
Security‑focused certifications (e.g. CompTIA Security+, Microsoft Certified Information Security Administrator Associate) highly desirable
What You’ll Bring
You are a technically strong and security‑focused infrastructure specialist who thrives in complex environments. You bring a structured, process‑driven approach, combined with the ability to influence and deliver across cross‑functional teams. You are equally comfortable operating at a strategic level and executing hands‑on technical work.
Why Join
Work on critical infrastructure within a high‑availability environment
Play a key role in shaping and delivering security strategy
Collaborate with experienced technical and cyber security professionals
Opportunity to influence architecture, standards, and operational maturity
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