We may have a requirement where we would use auth0 as identity store in both US and EU region. Is this possible and if so what is the recommended way to accomplish such a feat?
The Auth0 service is available in both the US and EU regions as that allows for it to be closer to the end-users and sometimes may also be a requirement due to laws. However, this is just an an option when setting up a tenant/domain; a choice of region. In conclusion, if you need separate identity stores in US and EU then just have one tenant in each region in order to benefit from being closer to your users. If on the other hand you need a common identity, then you need to have a single tenant/domain as end-user identities are tied to a specific tenant/domain and in this case you would have to choose a single region. A final note, if your requirements are complex and around where the data needs to stored in terms of countries then you may want to contact sales directly so that the full scenario can be discussed and all options considered.