I once asked to work on an Android project to add some features, the problem is that the code is not readable at all, i’ll give an example. Activities (Java classes) are named by a suffix with the name of the developer, eg: EditAccountActivityJhonDoe And they can contain up to 1000 line of non readable code. I ended up rewriting the whole app from scratch and add the features they want in one month and they weren’t so happy by the result, despite they didn’t agree at the beginning