This Microsoft Ignite session, delivered by Deborah Chen, Jeffrey Ilse, and Andrew Liu, showcases Sitecore's approach to building a scalable, secure, and cost-effective SaaS platform on Azure, with a focus on Cosmos DB architectural patterns.

How Sitecore Built a Scalable Isolated SaaS Platform on Azure

Speakers: Deborah Chen, Jeffrey Ilse, Andrew Liu

This advanced session from Microsoft Ignite 2025 explores Sitecore's transformation to a multi-tenant SaaS platform leveraging Azure services, particularly Cosmos DB. The key topics and practices discussed include:

SaaS Transformation Journey

• Introduction to Sitecore's API-first commerce platform, OrderCloud
• Challenges of global deployment and benefits of compliance-driven regional architecture

Data Tier Design Patterns

• Comparison of two Cosmos DB tenancy strategies:
  • DB-per-Tenant Pooling: Each tenant receives a separate database instance
  • Partition-Key-per-Tenant: Multiple tenants share a database, separated by partition keys
• Analysis of cost implications, TCO, and isolation provided by each model
• Security posture considerations when selecting a tenancy strategy
• Real-world trade-offs between cost, performance, and customer isolation

Operational Best Practices

• Employing the bulkhead pattern to isolate regions and customers, improving reliability
• Managing event overflow and handling AI pipeline costs
• Integrating circuit breakers and comparing SaaS models for robust architecture

Cost Optimization & Monitoring

• Using dashboards and query tools to monitor large-scale Cosmos DB fleets
• Identifying unused database accounts and pursuing cost-saving measures with autoscale analysis

API Management and Custom Solutions

• Addressing API management questions and sharing the architectural rationale for custom-built integration

Additional Resources

• Further explore Microsoft Fabric Data Engineering Plan: ignite25-plans-MicrosoftFabricDataEngineeringPlan
• Watch more sessions from Microsoft Ignite at ignite.microsoft.com

Key Takeaways:

• Strategic choices in Cosmos DB multi-tenancy design significantly impact scalability, costs, and isolation.
• Use of deployment stamps and bulkhead patterns enhances platform reliability and regional compliance.
• Operational monitoring and cost controls are essential for managing large, multi-tenant SaaS solutions on Azure.