Senior Architect - Microsoft Exchange Online

About the role

This job is responsible for defining an architectural vision and solution that supports the strategic outcomes of the Business’ Products and Services. Key responsibilities include defining the target operating environment, designing for client resiliency, assisting with solution design, and defining non-functional requirements. The role works with stakeholders and service providers aligned to the Business’ strategic objectives, evaluates the impact of strategic design decisions, and contributes to the architecture roadmap.

Responsibilities

• Works across the business, operations and technology to create the solution intent and architectural vision for complex solutions and prioritize functional and non-functional requirements into a technology backlog to enable the technology roadmap and functionality to support evolving capabilities and services
• Contributes to the creation of the architecture roadmap of defined domains (Business, Application, Data, and Technology) in support of the product roadmap and the development of best practices including standardized templates
• Clarifies the architecture, assists with system design to support implementation, and provides solution options to resolve any architectural impediments
• Facilitates solution driven discussions, leads the design of complex architectures, and finds creative solutions through knowledge of domain, practical experiments, and proof of concepts while ensuring architecture is flexible, modular, and adaptable
• Educates team members on the technology practices, standardization strategies, and best practices to create innovative solutions
• Supports the team as needed to select the technology stack required for solutions and helps select preferred technology products
• Performs design and code reviews to ensure all non-functional requirements are sufficiently met (for example, security, performance, maintainability, scalability, usability, and reliability)

Architecture and Solution Design

• Design and own Exchange Online architectures, including:
  • Hybrid Exchange (Exchange 2016/2019 → Exchange Online)
  • Coexistence and staged migration models
  • Multi-geo tenant design and mailbox placement strategies
  • High availability, disaster recovery, and service resilience
• Define standards for:
  • Mailbox sizing and quotas
  • Shared mailboxes, resource mailboxes, and service accounts
  • SMTP relay and application integrations
  • Transport rules and mail flow architecture

Migration and Modernization

• Lead large-scale Exchange migrations, including:
  • On-premises Exchange to Exchange Online
  • Cross-forest or tenant-to-tenant migrations
  • Public folder modernization or replacement
• Design and execution:
  • Migration throughput and throttling strategies
  • Cutover, staged, and hybrid migration plans
  • Rollback and business continuity strategies
• Partner with desktop, identity, and network teams to ensure seamless end-user experience

Security, Compliance and Governance

• Architect secure messaging solutions aligned to enterprise standards:
  • Email authentication (SPF, DKIM, DMARC)
  • Anti-spam, anti-phishing, and malware protection
  • Secure mail flow and transport encryption
• Integrate Exchange Online with:
  • Microsoft Purview (retention, eDiscovery, DLP)
  • Microsoft Defender for Office 365
  • Microsoft Entra ID Conditional Access
• Support regulatory requirements such as:
  • Legal hold and litigation workflows
  • Journaling, retention, and supervision
  • Data residency and cross-border considerations

Operations and Service Excellence

• Define operational models for Exchange Online:
  • Monitoring, alerting, and incident response
  • Change and release management
  • Capacity planning and service health governance
• Troubleshoot complex issues involving:
  • Mail flow and transport delays
  • Client connectivity (Outlook, mobile, ActiveSync)
  • Hybrid configuration and directory synchronization
• Drive continuous improvement of service reliability and performance

Required Qualifications

• 8+ years in enterprise messaging or collaboration architecture
• 4+ years hands-on experience with Exchange Online
• Deep expertise in:
  • Exchange Server 2016/2019 (hybrid and coexistence)
  • Exchange Online mail flow and transport
  • Exchange Edge services
  • Autodiscover, DNS, and SMTP architecture
  • Email hygiene systems (DLP, Malware, Spoofing, Phishing, Tagging)
• Strong understanding of:
  • Microsoft 365 identity integration
  • Hybrid connectivity and network dependencies
  • Client protocols (MAPI, REST, ActiveSync)
• Proven experience delivering large-scale migrations (10k+ mailboxes preferred)
• Strong understanding of:
  • Throttling, concurrency, and migration optimization
  • End-user impact management and communications

Desired Qualifications

• Strong architectural and analytical thinking
• Excellent documentation and communication skills
• Ability to explain complex technical topics to non-technical stakeholders
• Comfortable operating at both deep technical and executive levels

Preferred Qualifications

• Microsoft certifications such as:
  • MS-100 / MS-101
  • Messaging or Microsoft 365 certifications
• Experience in regulated industries (financial services, healthcare, government)
• Exposure to:
  • Microsoft Purview (eDiscovery, retention, DLP)
  • Microsoft Defender for Office 365
  • Tenant-to-tenant or divestiture migrations
  • Microsoft Outlook on Mobile
• Familiarity with:
  • Multi-geo Microsoft 365 deployments
  • Zero Trust messaging principles

Skills

• Analytical Thinking
• Architecture
• Result Orientation
• Solution Design
• Technical Strategy Development
• Application Development
• Collaboration
• Data Management
• DevOps Practices
• Risk Management
• Agile Practices
• Automation
• Influence
• Solution Delivery Process
• Test Engineering