Fail fast!
...sorry for the sarcasm but this is a message student engineers internalize in part because it is pushed by companies they want to work for but can't explain why. They don't have strong boundaries between why it might he a justifiable philosophy for Facebook but not for Boeing.
But in response to your comment, engineers have a very clearly defined set of rules, collectively called "the code". As long as they design to them you'll be free of criminal negligence (at least during the design & development phase, things get a little murkier in construction).
More to the point, engineering for the real-world means layer upon layer of uncertainty. e.g. civil/structural engineers use materials we can't model (we use pretty-good approximations for concrete behavior) in conditions which are unknown (soil) to resist forces we can't predict (weather, earthquakes, dynamic response to loading). How does the code deal with all this uncertainty? Slap safety-factor after safety-factor onto everything. Whoever comes up with a method for more effectively dealing with this stuff will make millions.
The most obvious example being that we design structures to resist a 1-in-100 year storm. In other words, we expect a structure to be within spitting distance of failure every hundred years. But as long as you design to that standard, you're fine.