Four concepts on one platform isn't that a hard job for the dev's? What if the system will crash because of knotting of the features of the platform? How can you will assist and cater such kind of problem in the system?, it is possible actually because of system overload and overly using of users in the same time.
Is it four concepts or more? You have a point there JoshJelly but take note that Smart City project will be using powerful servers that can surely handle this kind of failure that you have said. There is also a redundancy server which can back-up if one server fails. I am confident that SmartCity will make necessary precautionary actions like this. And besides, there are new technologies on the market already available to apply on their platform to make it more stable and secure.