How does Rails handle large-scale system design for multi-tenant SaaS platforms?

Rails supports multi-tenant SaaS using tenant isolation strategies like shared DB, schema separation, or database-per-tenant.

Multi-tenant SaaS architecture must balance cost, scalability, and isolation. Rails supports shared database with tenant_id filtering, schema-based isolation using PostgreSQL schemas, or full database-per-tenant isolation. Each approach has trade-offs in performance, security, and operational complexity. Tenant context is often managed using middleware or Current attributes.