You can't build a "system that never stops" by luck. You do it one of two ways: either you suffer a whole lot of failures, patching the boat as it springs more leaks; or you engineer it to be stable from the beginning. We've got a well-developed field of Reliability Engineering that we can use to deal with many common problems.

Reliability Engineering matters. You'll learn the essential techniques to keep your system from falling apart due to basic failures.

It can only go so far, though. We will encounter boundaries when we work with large scale, interdependent systems, or feedback loops. You'll learn how to recognize those boundaries, and some heuristics you can apply to stay on the safe side of them.