Platform
Multi-tenancy, explained
The alternative is one installation per customer, which is simpler to reason about and considerably more expensive to run, patch and monitor. Multi-tenancy trades that operational cost for a correctness obligation: every read and every write must be scoped to the right organisation, every time, with no exceptions anywhere in the codebase.
The obligation is harder than it sounds because it is a whole-system property rather than a feature. A single endpoint that forgets its scope, a single background job that queries by identifier alone, a single log line or metric labelled with the wrong organisation, and the guarantee is gone — while every test that checks a feature still passes.
How Enclessa uses it
Enclessa is a multi-tenant hosted service: one installation serves every customer organisation, each reachable at its own hostname. The organisation is taken from the session at a single choke point and never from a parameter a caller supplies. How that is proven rather than asserted is described under tenant isolation.