Comment by kossTKR

  "This is one possible characteristic of complex systems: they behave in ways that can hardly be predicted just by looking at their parts, making them harder to debug and manage."

To be honest this doesn't sound too different from many smaller and medium sized internetprojects i've worked on, because of the asynchronous nature of the web, with promises, timing issues and race conditions leading to weirdness that's pretty hard to debug because you have to "playback" with the cascading randomness of request timing, responses, encoding, browser/server shenanigans etc.