In our SaaS system we’re dividing users into separate “pools” according to the customer that originally “owns” the user. We’re using “email addresses plus ID of owning organisation” to identify users, rather than just email addresses – so duplicate email addresses can exist between customers (don’t ask). Users arrive at the site on various subdomains, and we use these subdomains to identify the “user pool” we’re authenticating the user against.
My question: is there any established name for this pattern or something similar?
Cheers!
“home-realm-discovery” is a common term for identifying what tenant a user belongs to in a multi-tenant SaaS application. It’s most often talked about in the context of Federated Identity but applies in your case too. Using a sub-domain like you’re doing is a common practice.