The problem is as follows. We have 2 native apps (ios and android) connected to a Firestore backend. Our current data model stores the information about the users spread across 5 different collections (profile data, user answers, user legal documents, etc). This means, often times, when we need to query data about the user we need to make several queries and manually join them together to get what we need. It’d be much simpler for us to have all the information stored in a single collection. This is a problem we have now, and as our business will continue to evolve, we will have more situations where we need to change the structure of the data model.
Currently, we use the Firestore API to query the user’s data in the frontend to have real-time updates. ATM we don’t use custom endpoints and therefore we don’t have any kind of versioning in place.
Are there any best practices or strategies to perform such a data model migration without forcing the user to upgrade to the latest version of the app?
We can think of some solutions:
- Use versioned-endpoints and forget about real-time updates (decouple the FE from the BE)
- Migrate the current data to the new data model while keeping the old collections still actives to serve old versions of the app. Additionally, write some cloud function listeners to keep the 2 models in sync (whenever an old version of the app writes in any of the 5 user collections, copy that data to the new data model)
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The problem of an evolving data model and having several FE’s consuming the data is extremely common. The normal best practice would be to have a versioned endpoint that the FE communicate to, to break the direct dependency on the data model. However, it doesn’t seem like Firebase have a set best practice for this. This sounds a bit strange to us, as it is such a common problem to have, and that Firebase solves so many other common challenges out of the box.
What are we missing?
Related questions: https://www.reddit.com/r/Firebase/comments/dyhzlv/best_practices_of_versioning_with_a_firestore/
Thanks!