Much programming is more art or craft than engineering.

For example, what separates a mechanic from an engineer? They are often working on the same project, and appear to be doing the same thing. In my view, a mechanic follows rules of thumb, eyeballs a design, etc. An engineer applies math and derives design, or checks the design using math. A mechanic will say "this beam looks thick enough to hold the load", and engineer can do a calculation to select the correct thickness for the load.

For software, a programmer can tell you that quicksort is faster. An engineer can tell you why it is faster, and be able to calculate how much faster it is.