What is a Tenant Isolation?

In a multi-tenant SaaS platform, many customers share the same application code, database clusters, and compute infrastructure to keep costs down. Isolation is what prevents that sharing from becoming a leak: it can be enforced at the data layer, with every query scoped by a verified tenant ID rather than a client-supplied one, at the compute layer, with separate containers or credential stores per tenant, and at the network layer, with per-tenant secrets and access policies. Weak isolation is one of the most common causes of serious security incidents in multi-tenant software; a single unscoped query or a shared credential can expose one customer's data to another. Strong isolation is also what auditors look for under frameworks like SOC 2 and ISO 27001, since it directly maps to the confidentiality and access-control criteria those standards test.