I've been the incoming dev on a project like this. The CTO (a brilliant architecture guy who hadn't written code in a long time) built a proof of concept in a s

I've been the incoming dev on a project like this. The CTO (a brilliant architecture guy who hadn't written code in a long time) built a proof of concept in a spaghetti of c# and PHP (drupal). It was an absolute mess, but it worked. It was actually impressive that he was able to build it all solo, and obviously with a team and infinite time he could have made the code pretty. You have accomplished the same thing, which is building and shipping a whole app, which some of these incoming devs have not. Your job now can be to guide these devs in refactoring the individual pieces of the app while you keep an eye on the bigger picture. Think of a conductor in an orchestra...he can't play every instrument perfectly, but he can guide the individual musicians.