Design a Multi-Tenant SaaS Database (DynamoDB)

Design a DynamoDB schema for a multi-tenant SaaS application with strong tenant isolation and varying usage patterns.

Functional Requirements

• Complete data isolation between tenants
• Support for tenant-specific configurations
• User management within each tenant
• Resource quotas and usage tracking
• Audit logging of all operations
• Cross-tenant admin operations (for platform admins)

Non-Functional Requirements

• Consistent performance regardless of tenant size
• Scale from small to enterprise tenants
• Cost attribution per tenant
• Support thousands of tenants

Questions to Consider

• How do you ensure tenant isolation at the data model level?
• What partition strategy prevents noisy neighbor problems?
• How do you handle tenants with vastly different data volumes?