I was wondering if it’d make sense and how feasible it is to have a multi-tenant project composed of 2 phoenix apps.

One app is just an API with ash_json_api to serve the end-users, and the other is a dashboard on top of the same database, for the tenants.
The dashboard app with a AshAuthentication set up for the main users (magic link login) and the API app another AshAuthentication setup with email/password.

Both apps use the same database with schema-based multitenancy, but the dashboard also operates on the public schema for the main users (for user creation and login).

This way I could cleanly separate the 2 sides of the system, but then it’d be a mess having to keep in sync the shared domain and resources. In one I’d have to put json api routes and in the other no.

I bet there is something I’m missing and I could be able to derive the 2 apps from the same resources. Right now it’s one single otp_app that offers both json api routes and html dashboard routes. One problem is that Ash authentication is picking up both the main-user and end-user resources when accessing the dashboard (it shows both magic link and email/pass at login, and the conn has both current_user and current_end_user).

I’d like to avoid that. Also what if I need to start scaling and replicate the API? The dashboard side won’t need to scale up, probably , while the api side might receive a lot of traffic. For instance I could have 1 single user that in turn has 1 million end-users. The dashboard is used by 1 and the api is used by 1 million.

So, my question is basically how to organize such project. Would it be possible to separate the project into a multi app monorepo project or an umbrella project where I have:

• 1 otp_app with all the shared domain and resource (with both dashboard-specific actions and json api routes);
• 1 app for the dashboard with the router for the dashboard routes + the main accounts domain and resource with ash authentication on top;
• 1 app for the API which has a very simple router to just redirect to the AshJsonApi Router in the shared app, plus its own end-user domain+resource with another ash authentication.

I didn’t try anything yet and it might be a silly idea that won’t work. I’d like to know from more experienced people how to organize a project like that with ash.