> You might notice that these real engineering jobs also don't have a way to verify the product via tests like that though, which was my point.

The electrical engineers at my employer that design building electrical distribution systems have software that handles all of the calculations, it’s just math. Arc flash hazard analysis, breaker coordination studies, available fault current, etc. All manufacturers provide the data needed to perform these calculations for their products.

Other engineering disciplines have similar tools. Mechanical, civil, and structural engineers all use software that simulates their designs.

> You might notice that these real engineering jobs also don't have a way to verify the product via tests though, which was my point.

Are you sure? Simulators and prototypes abound. By the time you’re building the real, it’s more like rehearsal and solving a fe problems instead of every intricacy in the formula.