Senior Microsoft 365 Migration Lead

Location: Remote, Eastern Time business hours

Engagement type: Contract with potential for extension and/or conversion

Commitment: Full-time project allocation

We are seeking a hands-on Microsoft 365 Migration Engineer to support the secure integration of acquired organizations into an enterprise Microsoft 365 environment. This role partners with IT M&A teams, technical stakeholders, vendors, and acquired-company contacts to assess environments, plan and execute migrations, and maintain employee productivity throughout the integration process.

The ideal candidate brings strong technical expertise in Microsoft 365, tenant-to-tenant migrations, identity and access management, and migration tools, along with the ability to manage complex dependencies and communicate effectively.

• Assess source environments, define migration scope, and identify licensing, identity, security, and operational risks.
• Plan and execute migrations across Exchange Online, Microsoft Teams, SharePoint Online, and One Drive, including pilots, sequencing, cutover, validation, stabilization, and operational handoff.
• Support Day 1 email readiness by validating mailbox access, mail flow, and email-client functionality.
• Configure and manage migration tools, accounting for licensing, permission mapping, throughput, and throttling.
• Coordinate technical dependencies with internal teams, vendors, and acquired-company stakeholders.
• Test and validate migration outcomes, review logs, troubleshoot issues, and document exceptions to minimize business disruption.
• Communicate migration progress, risks, issues, and recommendations to technical and business stakeholders.
• Develop and improve migration runbooks, documentation, tools, and repeatable processes to support future acquisitions.

• Hands-on experience leading enterprise Microsoft 365 and tenant-to-tenant migrations, including M&A integrations involving organizations with 100 or more users.
• Experience with Bit Titan, Quest On Demand, Share Gate, or comparable migration tools, including tool selection, licensing, permission mapping, throughput, and throttling.
• Strong knowledge of Exchange Online, including mailbox migrations, mail flow, domains, DNS, shared mailboxes, distribution lists, and email-client readiness.
• Strong knowledge of Microsoft Teams, SharePoint Online, and One Drive, including user and group permissions, external sharing, and collaboration dependencies.
• Strong knowledge of Microsoft Entra , authentication, multifactor authentication, Conditional Access, and access controls.
• Ability to assess data volumes, licensing requirements, identity dependencies, and migration risks and translate findings into actionable migration plans.
• Experience testing and validating migrations, reviewing logs, troubleshooting technical issues, and documenting exceptions.
• Clear communication and strong documentation skills, with a collaborative and accountable approach to changing priorities.
• Availability for occasional travel and after-hours support during cutovers and critical milestones.

• Experience delivering large-scale Microsoft 365 transformations or supporting multiple acquisitions concurrently.
• Experience completing migrations for 100 or more users within condensed timelines.
• Exposure to international M&A integrations, cross-border data residency, compliance, and collaboration requirements.
• Experience migrating from Google Workspace, on-premises Exchange, or hybrid environments.
• Experience in professional services, accounting, financial services, or other regulated environments

Aberdeen Advisors is an equal opportunity employer. All qualified applicants will receive consideration without regard to race, color, religion, sex, pregnancy, sexual orientation, gender identity or expression, national origin, age, disability, veteran status, or any other characteristic protected by applicable law.