Provide expert-level technical support to resolve complex hardware, software, and network issues escalated from L1 and L2 teams. Perform in-depth troubleshooting and root cause analysis to identify the underlying causes of critical incidents. Develop and implement permanent solutions, including patches, workarounds, and configuration changes. Collaborate with development teams, vendors, and other IT departments to resolve issues and implement solutions. Manage and maintain critical IT infrastructure and applications to ensure stability and reliability. Monitor system performance, identify potential issues proactively, and implement preventative measures. Create and maintain comprehensive technical documentation, including knowledge base articles, troubleshooting procedures, and system architecture diagrams. Provide guidance, mentorship, and training to L1 and L2 support engineers. Participate in on-call rotations to provide 24/7 support for critical incidents. Contribute to the development and improvement of support processes and procedures. Stay up-to-date with the latest technologies and industry best practices. May be involved in system design, implementation, and upgrades. Communicate effectively with customers and internal stakeholders regarding issue status and resolution. Key skills : Strong troubleshooting skills in Windows Experience with networking protocols, firewalls, VPNs, and security best practices . Hands-on experience with Active Directory, DNS, DHCP, Office 365, print server and cloud platforms (Azure) . Hands-on Experience with Microsoft Office 365 and Azure AD Proficiency in ticketing systems (Autotask) . Familiarity with virtualization technologies (Hyper-V, etc.) . Knowledge of SQL databases and scripting. Must have work experience with USA and Australia client Excellent communication and customer service skills.