Multi-Tenant Architecture Patterns for SaaS Applications

Multi-tenancy is the defining architectural characteristic of SaaS. Getting it right determines your platform's security posture, scalability ceiling, and operational costs.

Isolation Strategies Compared

The spectrum ranges from full isolation (database per tenant) to full sharing (shared tables with tenant_id columns). Your choice depends on compliance requirements, customer expectations, and cost constraints.

Row-Level Security (RLS)

PostgreSQL's Row-Level Security policies enforce tenant isolation at the database level, preventing data leaks even if application code has bugs. This is the gold standard for shared-schema multi-tenancy.