It seems to me that a key requirement for engineering would be that there are formal design specifications for the system (such as a car or bridge) as well as i

It seems to me that a key requirement for engineering would be that there are formal design specifications for the system (such as a car or bridge) as well as its constituent components. There are also usually mathematical models of the system that can predict its behavior and performance as accurately as needed for the application. Many modern software systems seem to lack such specifications or models. In these cases software development seems more like tinkering than engineering.