Tier 3 Engineer

Hamilton Barnes ?; Denver (CO); On-site; USD 100,000 - 150,000; Full time

Job summary

Hamilton Barnes is seeking a Tier 3 Engineer to act as a senior escalation point across infrastructure, Microsoft cloud, networking and security. This hands-on role focuses on solving complex technical problems, eliminating recurring issues, and providing technical leadership across high-complexity projects.

The position requires strong Windows/AD, Azure, M365, and security expertise with the ability to mentor junior engineers and deliver runbooks for ongoing operations.

Qualifications

• 5+ years of MSP/IT consulting experience.
• 2+ years in a senior/escalation/Tier 3 role.
• Expert Windows Server and Active Directory administration.
• Experience with Microsoft 365, Entra ID, Exchange Online, and Defender.

Responsibilities

• Serve as senior escalation point for high-severity incidents.
• Perform root-cause analysis and fix recurring infrastructure issues.
• Lead technical responses for outages, identity, and security incidents.
• Design and maintain MS cloud and on-prem infrastructure.
• Mentor Tier 1/2 engineers through escalations and training.
• Create runbooks and documentation to reduce escalations.

Skills

MSP experience

Senior escalation

Problem solving

Tools

PowerShell

RMM tools

Azure

Microsoft 365

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,