Senior Infrastructure Engineer

The Senior Infrastructure Engineer (L3) is the top-tier escalation point within the Managed Services Practice (MSP) engineering tier. This role owns the design, implementation, administration, and advanced troubleshooting of client environments with a primary focus on virtualization platforms, Microsoft 365 cloud services, and Active Directory / identity infrastructure. The L3 Engineer serves as the technical authority for complex incidents, architecture decisions, and project delivery across a diverse multi-tenant client base, while mentoring L1/L2 engineers and ensuring service quality, security, and documentation standards are met.

Local candidates are strongly encouraged to apply. This position is based in our Indianapolis, IN office, and relocation assistance or remote work is not available at this time.

• Act as the final internal escalation point for complex, high-impact incidents across virtualization, M365, and Active Directory workloads.
• Perform root-cause analysis on recurring issues and drive permanent corrective actions to reduce repeat ticket volume.
• Engage vendor support (Microsoft, VMware, Dell, etc.) on behalf of clients and manage the support lifecycle through resolution.
• Maintain ownership of Major Incidents, communicating technical status to internal teams and client stakeholders.
• Architect, deploy, and manage Scale Computing HCI, VMware vSphere (vCenter, ESXi, vSAN, NSX) and Microsoft Hyper‑V / Azure Stack HCI environments.
• Perform host provisioning, cluster configuration, vMotion/Storage vMotion, resource tuning, and capacity planning.
• Manage backup and disaster‑recovery integrations (Cove, Veeam, Datto, Azure Site Recovery) including failover testing and runbook validation.
• Lead hardware refresh, P2V/V2V migrations, and datacenter consolidation projects.

• Administer M365 tenants including Exchange Online, SharePoint Online, One Drive for Business, Microsoft Teams, and Defender/Compliance workloads.
• Design and implement Microsoft Entra  (Azure AD) configurations: conditional access, MFA, app registrations, B2B/B2C, and identity governance.
• Manage tenant‑to‑tenant migrations, hybrid Exchange/AD configurations, and Intune MDM/endpoint management.
• Configure and tune Microsoft Defender for Office 365, Purview, and DLP policies aligned to client security baselines.

• Design and maintain Active Directory forests, domains, sites, trusts, OU structures, and Group Policy Objects (GPOs).
• Manage AD replication, FSMO roles, DNS/DHCP, certificate services (AD CS), and AD‑integrated DNS at scale.
• Lead AD migrations, domain consolidations, forest recovery, and hybrid Entra  synchronization troubleshooting.
• Implement least‑privilege role models, tiered administration, and privileged access management (PAM) practices.

• Lead scoping, design, and execution of client infrastructure projects from statement of work (SOW) through handoff to support.
• Produce architecture diagrams, build documentation, and knowledge‑base articles to enable L1/L2 teams.
• Provide technical mentorship, peer review, and training to junior engineers; participate in onboarding and skills development.
• Participate in the on‑call rotation for after‑hours escalations and scheduled change windows.

• Apply CIS, NIST, and Microsoft security baselines to client environments and remediate findings.
• Conduct periodic health checks, patch management reviews, and vulnerability remediation across managed estates.
• Support client compliance initiatives (HIPAA, CMMC, SOC 2, etc.) with technical controls and evidence collection.

• 5+ years of progressive IT engineering experience, with at least 2 years in an MSP or multi‑tenant consulting environment.
• Deep expertise in VMware vSphere (vSphere 7/8) and/or Microsoft Hyper‑V / Azure Stack and other HCI administration.
• Strong Microsoft 365 administration experience with working knowledge of the Microsoft 365 admin centers, Power Shell, and Graph API.
• Advanced Active Directory and Entra  (Azure AD) engineering skills, including…