A well-established organisation with multiple UK sites is seeking a Senior IT Systems Administrator to take ownership of its IT infrastructure across a growing network of offices. This is a hands-on role ideal for someone who enjoys solving complex technical challenges and is looking for a genuinely supportive, value-driven culture. You'll be responsible for maintaining servers, networks, and systems, supporting users, and driving improvements in performance, security, and efficiency. ?? Key Responsibilities: Manage and resolve support tickets across teams Administer Windows/Linux servers, virtual environments, and network components Maintain Active Directory, SQL Servers, and telephony systems Implement cybersecurity best practices and disaster recovery plans Collaborate with internal developers and external IT partners ? What You'll Need: Experience within a similar role Strong experience with Windows Server and M365 Proficiency in networking and monitoring tools Excellent troubleshooting skills and a proactive mindset