The real-time functions in Firebase are not only suited for, but designed for large data sets . The fact that records stream in real-time is perfect for this. Performance is, as with any large data app, only as good as your implementation.
Read moreWhy is Firebase not good?
Firebase is not made for processing complex queries as it relies on a flat data hierarchy . Complicated queries like reversing the order of certain items cannot be executed using Firebase. On top of that, even when you go offline, your app might begin to underperform due to the concurrency.
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