As a young engineer, I had no doubt in my mind that engineers designed things, and fixed things, and analyzed things. I never thought for a moment about the difference between engineering and science… or the difference between engineering and anything else for that matter. Yet as I set about explaining the engineering profession to non-engineers (and young non-engineers at that), there grows a great mysteriousness about engineering duties.
Koen  notes that engineers are known by the products over which they toil:
Because the connection of the engineer with his completed design is so enduring and the connection with his use of method so fleeting, a person insists he is an engineer based on what he produces, irrespective of how he goes about it, instead of insisting that he is an engineer based on how he goes about it, irrespective of what he produces. In a similar fashion, the historian uses the existence of dams on the Nile, irrigation canals in various parts of the ancient world, gunpowder, and pottery to infer the existence of engineers and craftspersons in past civilizations. But behind each chemical, each road, each pot hides the common activity that brought it into being. It is to this unity of method that we must look to see the engineer in every man.
So while Koen would have us see each person as an engineer, Petroski  tells us that there are distinct differences between engineer and scientist:
Although there may be commonalities in principle and similarities in method, neither science nor engineering can completely subsume the other. This is not to say the self-declared or designated scientists cannot do engineering, or that engineers cannot do science, In fact, it may be precisely because they each can and do participate in each other’s defining activities that scientists and engineers—and hence science and engineering—are so commonly confused.
And perhaps most disheartening, is the assessment of Williams  that:
… the establishment of an autonomous engineering profession oriented toward ideals of broad social responsibility … has not happened and is not going to happen.”
At the very least, engineering is a “niche-y” profession. My experience has been that no two engineers carry out the same duties, even if they work for the same company. So my quest continues; I’ll keep reading, and attempting to sift out commonalities among the world’s multitude of engineering roles!