Senior IT Systems Administrator in Bristol

Senior IT Systems Administrator / Bristol (3 days on-site) / £50,000–£60,000 | DV Clearance Eligibility Required Take ownership. Solve complex challenges. Make IT better. TwinStream is looking for an experienced Senior IT Systems Administrator to help keep our IT systems secure, resilient and performing at their best. This is a hands-on senior role offering the autonomy to tackle complex technical challenges, drive improvements, introduce automation and support colleagues across a growing business. About TwinStream Founded in 2019 by engineers solving complex challenges within government organisations, TwinStream combines deep technical expertise with outstanding client service. We've since grown to more than 100 people across the UK, with colleagues working on-site, remotely and in hybrid environments. The Senior IT Systems Administrator Role You'll take senior operational responsibility for TwinStream's corporate IT estate, ensuring systems remain secure, reliable and fit for the future. Working alongside the IT Technical Lead, you'll turn technical priorities into practical improvements while using your expertise to resolve issues, guide colleagues and enhance service delivery. Your responsibilities will include: Managing the performance, resilience and lifecycle of cloud services, infrastructure, devices and applications. Administering Microsoft 365, Entra ID, identity and access management, endpoint security and corporate SaaS applications. Maintaining corporate networks, including firewalls, switches, wireless, VPN, DNS and DHCP. Implementing configuration changes, integrations and automation to improve efficiency and consistency. Monitoring service health, capacity, performance and security, proactively addressing risks and vulnerabilities. Leading complex incident resolution, root-cause analysis and security investigations. Coordinating patching, upgrades, backups, recovery testing and business continuity arrangements. Maintaining technical documentation, operational procedures, asset records and IT service-management standards. Mentoring colleagues, working with suppliers and stakeholders, and recommending improvements to support future priorities. What We're Looking For<...