Backend Multi-Tenancy

Purpose

Implement tenant isolation in a SaaS application using row-level, schema-per-tenant, or DB-per-tenant strategies with automated provisioning and safe migrations. The core challenge is guaranteeing that no tenant can access another tenant's data while balancing operational complexity, cost, and compliance requirements.

Architecture/Decision Trees

Isolation Strategy Decision Tree

Is regulatory compliance required (GDPR/SOC 2/HIPAA)?
  |-- YES --> Do tenants require full data separation?
  |     |-- YES --> DB-per-tenant (highest isolation)
  |     |-- NO  --> Schema-per-tenant
  |-- NO --> Expected tenant count?
        |-- < 100, B2B --> Schema-per-tenant
        |-- >= 100, B2C --> Row-level (shared database)
        |-- Mixed (B2B+B2C) --> Hybrid: row-level for B2C, schema for B2B