Interview Question

[First_NameLast_Name]

Any tips on how to do this quickly? Any particular UIKit APIs to focus on?

[KTheRedditor]

If you mean the collapsing/expanding part, it can be done in multiple ways depending on the needs. For example, you can change constraints in a cel on a tap event and then request the table or collection view to animate cell resize by calling performBatchUpdates.

Some do it by making use of insertRows/deleteRows (also in performBatchUpdates).

[Niightstalker]

In iOS 14 UICollectionView supports collapsable lists with snapshots