Realm Users & Authentication

Hello. I am setting up user authentication using Realm’s email/password application service, but there are a few things I’m confused about that I would like clarification on. I was not able to find these answers in the docs.

I am building a microservice-based application with all of my microservices connected to a gateway. One of these services is the account/authentication service where I have Realm’s Node.js SDK installed. I am able to successfully register a user and confirm their email, as well as log them in - but I want to understand more about what happens when a user logs in, as well as how/where the user object is stored in the first place.

When I started using Realm I assumed that the “user object” would actually be a collection added to my Atlas cluster, but it isn’t. That means the “user object” is being stored in a second database, and I’m curious as to why. I’m also curious to know why “custom data” is stored in my Atlas database instead of with the user object.

Next, I need to understand more about how Realm manages sessions. What type of session architecture does Realm use? I’d like to look it up to learn more, because I need to understand how to authenticate users throughout all of my microservices.

I appreciate anyone who takes the time to answer my questions. Thank you.