&gt; A monolithic system executing a given function is pretty much guaranteed to be simpler than a distributed system doing the same function.<p>And what about a monolithic system executing thousands of different functions?<p>If your app is a simple todo list, sure, go monolithic (but you should still delegate storage to some other tool). If it is much more complex than a todo list, then it is very likely that you have many packages containing many modules developped and maintained by many programmers. And if one glitch on one side of the monolith affects a remote module and functionalities depending on it, or even breaks down the whole monolith, then you should go microservices. Or split your code base. Or do whatever is needed so the thing can still move forwards, if slowly, without breaking apart at each little step.