Senior Infrastructure Engineer

Tokio Marine North America Services (TMNAS) provides professional support services to Tokio Marine Group companies in the United States, including Tokio Marine America, First Insurance Company of Hawaii, and Philadelphia Insurance Companies. Customer service is our focus and our passion! Tokio Marine North America Services adds value in all that we do, providing the best professional service to our business partners, allowing them to achieve their goals.

Our talented team delivers actuarial, audit, corporate communications, financial and investment, human capital services, information technology, legal, and payroll expertise to our customers.

Responsible for engineering, support, and continuous improvement of the Microsoft 365 ecosystem including hybrid Exchange (on-prem and Exchange Online), Teams, SharePoint Online, One Drive, Microsoft 365 Copilot, Viva suite, and Dynamics 365 integrations. This role serves as a Tier 3 escalation point for complex issues, supports multi-tenant environments, and drives automation, platform stability, and cross-tenant collaboration improvements.

• Provides Tier 3 (L3) escalation support for Microsoft 365 services including hybrid Exchange
• Troubleshoots complex issues across Exchange Online, Teams, SharePoint Online, One Drive, and integrations
• Diagnoses and resolves mail flow, connectors, transport rules, and hybrid connectivity issues
• Supports Microsoft 365 Copilot including licensing, access, and application integration troubleshooting
• Supports Dynamics 365 and SaaS platform integrations with Microsoft 365
• Supports multi-tenant environments including cross-tenant collaboration, identity, and access scenarios
• Troubleshoots cross-tenant issues including sharing, authentication, and mail routing
• Supports tenant-to-tenant migrations, domain cutovers, and coexistence scenarios
• Performs root cause analysis and implements long-term solutions for recurring issues
• Executes automation using Power Shell and supports Graph API-based automation
• Supports M365 security configurations including Conditional Access, DLP, and retention policies
• Creates SOPs, QRGs, and technical documentation to improve supportability
• Partners with operations teams to reduce repeat incidents and improve escalation handling
• Collaborates with Infrastructure, Security, and Application teams on cross-platform initiatives
• Supports ongoing platform improvements and modernization efforts across the M365 environment
• Participates in on-call rotation and after-hours support as required
• Ability to document processes and contribute to knowledge sharing

• Bachelor's degree preferred
• Experience supporting Microsoft 365 environments including Exchange Online, Teams, SharePoint Online, and One Drive
• Hands‑on experience with Exchange Hybrid (on‑prem Exchange + Exchange Online)
• Experience with mail flow, connectors, and transport troubleshooting
• Exposure to Microsoft 365 Copilot and Viva suite
• Experience with multi‑tenant M365 environments or cross‑tenant collaboration
• Experience with tenant‑to‑tenant migrations or coexistence scenarios
• Working knowledge of Power Shell and automation scripting
• Understanding of Entra  (Azure AD), including identity and access management
• Relevant certifications:
  Microsoft 365 Certified:
  Administrator Expert (MS‑102) demonstrating the ability to design, deploy, and manage Microsoft 365 services across Exchange Online, Teams, SharePoint Online, and One Drive;
  Microsoft Certified:
  Identity and Access Administrator Associate (SC‑300) for expertise in Entra , conditional access, and identity governance;
  Microsoft Certified:
  Azure Administrator Associate (AZ‑104) to support hybrid integrations and Azure dependencies;
  Microsoft Certified:
  Security Operations Analyst Associate (SC‑200) or equivalent security certifications focused on threat detection, response, and compliance; and Microsoft Certified:
  Endpoint Administrator Associate (MD‑102) for endpoint management and device compliance. Certifications in Teams administration (MS‑700), security and compliance, and emerging areas such as Microsoft 365 Copilot or AI administration are also preferred
• Familiarity with…