There's a mistake many junior devs (and sometimes mid and senior devs) make where they confuse hiding complexity with simplicity - using a string instead of a w

There's a mistake many junior devs (and sometimes mid and senior devs) make where they confuse hiding complexity with simplicity - using a string instead of a well defined domain type is a good example, there is a certain complexity of the domain expressed by the type that they don't want to think about too deeply so they replace with a string which superficially looks simpler but in fact hides all of the inherent complexity and nuance. It causes what I call the lumpy carpet syndrome - sweeping the complexity under the carpet causes bumps to randomly appear that when squashed tend to cause other bumps to pop up rather than actually solving the problem.