Senior System Administrator

GuideIT is a US based technology services company focused on providing value to its customers through technology alignment and optimization. We are currently looking for a Senior System Administrator  to join our team.
We are seeking a highly skilled and motivated Senior System Administrator with a strong background in server infrastructure, cloud platforms, and enterprise collaboration services. The ideal candidate will have 5+ years of hands-on systems administration experience and deep expertise in Windows Server and Active Directory, public cloud infrastructure with an emphasis on AWS and secondary exposure to Azure, and Microsoft 365 administration across Exchange Online, SharePoint Online, Teams, Intune, and Entra ID.
Primary duties - Administer, maintain, and support server and cloud infrastructure as directed by the client’s designated lead.

- Provide services focused on systems build-out, documentation, support, and new environment and site deployments.

- Deploy, configure, and maintain infrastructure and platform services, including but not limited to:

- Windows Server, Active Directory, DNS, DHCP, Group Policy, and file and print services.

- AWS compute, storage, networking, and identity services (EC2, S3, EBS, VPC, IAM, Route 53, CloudWatch).

- Azure IaaS, Entra ID, and hybrid identity and directory synchronization.

- Microsoft 365 workloads, including Exchange Online, SharePoint Online, OneDrive, Teams, and Intune.

- Supporting network services such as VPNs, load balancers, and firewall policy changes.

- Perform system maintenance and upgrades, including applying service packs, patches, hot fixes, and security baselines across on-premises and cloud estates.

- Monitor system, platform, and network performance to ensure availability and reliability.

- Conduct resource monitoring, trending, and capacity planning across server, storage, and cloud workloads, including cloud cost and consumption review.

- Administer backup, replication, and disaster recovery processes, and participate in periodic restore testing.

- Automate recurring administrative tasks using PowerShell, Bash, or comparable scripting and infrastructure-as-code tooling.

- Adhere to established configuration and change management policies, ensuring all changes are reviewed, approved, and successfully implemented.

- Collaborate with the company’s security team to select and implement security tools, policies, and procedures, including identity, endpoint, and cloud posture controls.

- Provide escalation-level technical support for system, cloud, and network-related issues within strict SLA windows.

- Mentor junior administrators and support staff, and contribute to runbooks, standards, and knowledge base documentation.

 required skills - 5+ years of hands-on system administration experience in enterprise or managed services environments.

- Expertise in Windows Server administration, including Active Directory, Group Policy, DNS, DHCP, certificate services, and MFA.

- Hands-on experience administering AWS infrastructure (EC2, S3, VPC, IAM, Route 53, CloudWatch), with secondary working knowledge of Microsoft Azure.

- Proficiency administering Microsoft 365, including Exchange Online, SharePoint Online, OneDrive, Teams, Intune, and Entra ID (Azure Active Directory).

- Working knowledge of networking technologies, including routers, switches, and firewalls (Cisco, Meraki, Palo Alto).

- Understanding of routing, switching, and VPN technologies, as well as TCP/IP, DNS, DHCP, SMTP, IMAP, POP3, and other communication protocols.

- Experience using PowerShell or other scripting tools to improve administrative efficiency.

- Experience with virtualization platforms such as VMware vSphere or Hyper-V.

- Strong familiarity with ITIL standards and maintaining compliance in regulated environments.

- Knowledge of ticketing systems with a proven ability to manage and resolve tickets promptly.

- Strong communication and