As a Third Line Engineer, you will serve as a senior technical specialist within the IT team, responsible for resolving the most complex and critical issues that cannot be addressed by First or Second Line support. You will play a key role in maintaining and improving the organisation’s IT infrastructure, performing deep-dive diagnostics, root cause analysis, and implementing long-term solutions. In addition to supporting escalated incidents, you will contribute to system design, strategic projects, and continuous service improvement. Key Responsibilities: Expert-Level Support & Issue Resolution Take ownership of high-level, complex incidents and problems escalated from Second Line Support Perform in-depth diagnostics and root cause analysis across infrastructure, systems, and applications Develop and implement long-term fixes and preventative measures to reduce repeat incidents Infrastructure Management & Improvement Maintain, monitor, and optimise servers, storage, networking, and virtual environments Assist with infrastructure upgrades, patching, backups, and disaster recovery planning Support the implementation of new technologies and contribute to infrastructure architecture decisions Collaboration & Technical Leadership Work closely with other IT teams and stakeholders to ensure consistent and high-performing IT services Provide technical mentorship and guidance to First- and Second-Line colleagues Participate in change management processes, ensuring minimal business disruption Project Work & Continuous Improvement Lead or support technical projects such as migrations, deployments, and security enhancements Identify opportunities to improve system reliability, performance, and scalability Document technical processes, known issues, and architectural decisions in the knowledge base Essential: Proven experience in a Third Line or senior infrastructure support role Strong expertise in server administration, networking, virtualisation, and storage solutions Solid understanding of IT security principles and best practices Ability to carry out detailed troubleshooting and perform root cause analysis Experience managing or contributing to technical projects and service improvements Proficiency in tools such as Active Directory, Group Policy, Office 365, Exchange, and Windows Server Excellent written and verbal communication skills, including documentation and reporting Desirable: Relevant certifications (e.g. Microsoft Certifications or similar.) Experience with cloud platforms (e.g. Entra, M365, Dynamics 365 Business Central Knowledge of scripting and automation tools (e.g. PowerShell, PowerApps) Exposure to ITIL frameworks and structured change management processes Experience working in a regulated or enterprise environment Key Attributes: Technically adept: Demonstrates deep technical understanding and a logical approach to problem-solving Proactive: Anticipates potential issues and recommends improvements before they impact services Collaborative: Works well across teams and supports the development of junior staff Detail-oriented: Thorough in documentation, analysis, and execution of technical tasks Resilient: Remains calm under pressure and focused on finding solutions in high-impact situations Doncaster based, UK - Hybrid (3 days a week in office)