Consider a scenario where the developer is required to write a custom directory tree. Each row contains a caret and a checkbox. When either of these are clicked, you&#x27;ll need to perform some sort of tree traversal to ensure integrity of the view -- for example, checking the checkbox on a row may require that all children as selected too. Additionally, you may need an upward traversal to the root to ensure the parents are either in a mixed or unchecked state.<p>If the developer doesn&#x27;t understand performance (or at the very least, basic tree operations like searching&#x2F;sorting&#x2F;traversing), they&#x27;re going to write some horrible code. Google and Bloomberg have their pick, they don&#x27;t want a shitty developer.