[klabb3]

> Things like having an incorrect data model.

Absolutely. Take a look at git. It's basically just a Merkle tree which is an ingenius data structure with a very simple set of entities and invariants. Almost every feature of git can be viewed as merely manipulating this structure. If you rolled your own, you may get a fast mvp, but chances are that your data model will be very inefficient or complex for coming features.

This goes both ways. Git doesn't have eg tracking of empty dirs, as a result of the data model (to my understanding). Saying no when it doesn't fit the model is also an important aspect.

As such, the data model can't be decoupled from almost anything else, including the UI. It's well worth spending some serious time researching and planning that. Or, if you're still not confident, you can always prototype a quick-and-ugly POC which contains your main features – that usually helps inform and build intuition about the problem.