[theomega]

I was a heavy user of Keycloak until a year ago and I can only recommend your setup if you are sure that the amount of realms is not growing. Every additional realm uses huge amount of memory in Keycloak. From how I understood the architecture, a lot of components (if not all of them) are initialized per realm.

We had huge problems modeling multi-tenancy through reals in Keycloak.

Take everything I'm saying with a grain of salt. But, if you are planning to have a lot of customers and realms, do a benchmark by creating a lot of realms and checking if you can use all of them in parallel. YMMV.