A CollectionViews developer primarily works on iOS applications, utilizing the UICollectionView framework to create and manage dynamic and customizable visual layouts. Their duties include designing, implementing, and debugging UICollectionViews, customizing cells, headers, and footers, and ensuring smooth interaction between the data source and the view. They also handle tasks such as managing selections, highlights, and performing animations. They ensure optimal user interface by implementing efficient scrolling and resizing. They collaborate with UX/UI designers and backend developers to provide an efficient and interactive user experience. They also keep up-to-date with Apple's latest technologies and updates.