Multi-tenant

In a multi-tenant solution every customer shares the same codebase, the same operations and often the same database, while each customer sees only its own data, users and settings. It is the standard architecture for SaaS, because one update reaches every customer at once and the running cost per customer stays low. Separation can be done at several levels: a tenant ID on every row with access rules in the database (for example row-level security), a separate schema per customer, or a separate database per customer. The choice is about isolation, cost and how easy it is to move or delete one customer's data. The alternative is single-tenant, where each customer gets its own installation, which gives stronger isolation but more to run.

In Norwegian context

For SaaS providers the architecture ties in with the GDPR: customers are usually the controllers of their own data, and the provider is the processor. It must be possible to export and delete one customer's data without touching the others.