Multi-Tenant SaaS, SSO & Access Control

SaaS architecture in which one customer can never see another’s data: tenant isolation, roles and permissions, row-level security, enterprise SSO with SAML and OIDC, and an admin back-office for your team.

Multi-tenancy touches every table, query, cache key and background job, so I settle it before the first feature. Isolation model. Most B2B products start well on a shared schema with a tenant ID on every row, enforced by PostgreSQL row-level security as a second line of defence behind the application’s own checks. Schema-per-tenant or database-per-tenant isolation costs more to operate but suits customers with data-residency or contractual isolation requirements. Many products end up hybrid — shared by default, dedicated for the largest customers — so I design to keep that move possible…