A more thoughtful Firestore data model.

A useful data review starts with the product in use. Walk through the main screens and write down what each one needs to load, how much data it needs and when that data must update. Include loading, empty and error states in the walkthrough.

Review queries and listeners alongside the code that creates them. Look for screens loading more information than they display, repeated requests and subscriptions whose lifetime is unclear. Use observations from the running app to decide what needs attention.

Make changes in small steps and compare the behavior before and after. Check that access rules still match the intended permissions and that the revised structure remains understandable. The goal is a model that serves the product clearly and gives the next developer a sensible place to continue.