Software crafting is very much like building a bridge back in the days before xrays were around to detect cracks in metal and before metallury and casting were

Software crafting is very much like building a bridge back in the days before xrays were around to detect cracks in metal and before metallury and casting were very reliable - that was back in the 1800s when anything made of metal could and did fail at any time - including bridges - quite often catastrophically. A high percentage of bridges folded, over time. How do you "engineer" what you can't measure (such as whether a metal beam is fatally flawed by a large crack inside?) You don't. We're getting there slowly.