Tier 3 Engineer

Hamilton Barnes ?; Green Bay (WI); On-site; USD 90,000 - 130,000; Full time

Job summary

Hamilton Barnes ? is seeking a Tier 3 Engineer for a well-established MSP client in Green Bay, WI. This hands-on role serves as the senior escalation point across infrastructure, Microsoft cloud, networking, and security, focusing on complex problems and architecture improvements.

You will lead major outages, perform root-cause analysis, mentor junior engineers, and design secure Microsoft 365 and on-premises environments while ensuring seamless transition to managed services.

Qualifications

• 5+ years of MSP/IT consulting experience
• 2+ years in a senior or Tier 3 capacity
• Experience with Windows Server and Active Directory

Responsibilities

• Serve as the senior escalation point for high severity incidents.
• Lead outages and security incidents with technical leadership.
• Design and maintain Microsoft cloud and on-prem infrastructure.
• Mentor Tier 1 and Tier 2 engineers through escalations and training.
• Develop runbooks and documentation to reduce recurring escalations.

Skills

MSP Experience

Senior Escalation

Windows Server

Active Directory

Group Policy

Microsoft 365

Entra ID

Azure Networking

Security

Tools

PowerShell

RMM Tools

Microsoft Defender

Exchange Online

Job description

Our client is a well-established Managed Services and IT consulting organization supporting a diverse portfolio of client environments. They are looking for a Tier 3 Engineer to serve as a senior technical escalation point across infrastructure, Microsoft cloud, networking, and security. This is a hands‑on role focused on solving complex technical problems, eliminating recurring issues, improving client environments, and providing technical leadership across high‑complexity projects.

Responsibilities

• Serve as the senior technical escalation point for complex and high-severity incidents.
• Perform root-cause analysis and permanently resolve recurring infrastructure issues.
• Lead technical response for major outages, identity failures, and security incidents.
• Design, implement, and maintain Microsoft cloud and on-premises infrastructure.
• Manage Windows Server, Active Directory, Group Policy, DNS, DHCP, and certificate services.
• Administer Microsoft 365, Entra ID, Exchange Online, Intune, SharePoint, and Teams.
• Design and maintain Conditional Access, MFA, privileged access, and least-privilege solutions.
• Configure and maintain business-class firewalls, switching, routing, VPN, wireless, and SD‑WAN environments.
• Manage EDR/XDR, Microsoft Defender, email security, patching, and vulnerability remediation.
• Design and maintain backup, disaster recovery, and recovery testing processes.
• Review technical designs, project scopes, dependencies, and implementation plans.
• Serve as technical design authority for major client projects and implementations.
• Lead hands‑on delivery of select high‑complexity infrastructure projects.
• Ensure completed projects transition effectively into managed services.
• Develop technical standards, security baselines, documentation, and network diagrams.
• Mentor Tier 1 and Tier 2 engineers through escalations, training, and knowledge transfer.
• Create runbooks and documentation to reduce recurring escalations.
• Automate administrative and remediation tasks using PowerShell and RMM tools.
• Improve monitoring and alerting to proactively identify and resolve client issues.
• Support client security reviews, compliance requirements, and cyber‑insurance assessments.

Required Skills

• 5+ years of experience within an MSP, IT consulting, or multi-client infrastructure environment.
• 2+ years operating in a senior, escalation, or Tier 3 capacity.
• Expert‑level Windows Server and Active Directory administration experience.
• Strong knowledge of Group Policy, DNS/DHCP, and certificate services.
• Hands‑on Microsoft 365 and Entra ID administration experience.
• Experience with Exchange Online, Intune, SharePoint, Teams, and Conditional Access.
• Working knowledge of Azure infrastructure, including VMs, networking, RBAC, and backup.
• Strong TCP/IP, VLAN, routing, and switching fundamentals.
• Hands‑on experience with business‑class firewalls and VPN technologies.
• Practical experience with EDR/XDR, email security, MFA,