Not sure if this counts as “going back” but I have been managing a legacy project that is built like this for the past year or two. I hated it at first, but now I’m starting to appreciate it. My approach is to try to put as much as possible in php, but for parts of the page that are going to be manipulated by js/jquery, just have php pass the data as json and build that portion of the dom on the front end.
