UICollectionViewLayout From Scratch

UICollectionView is one of the most popular components in iOS development, and often the standard behaviour is not enough: you need to change the arrangement of elements, add animations, decorative elements, change the standard behaviour. The collection layout and the UICollectionViewLayout class are responsible for all of this. 

Last year I spent several months to understand the issues of creating my own UICollectionView layouts and applied all this knowledge in VK Market.