Levels to Programming
Putting things in this hierarchy seems to be too ambiguous, since there are too many overlaps within concepts, algorithms and sub fields in programming.
Nonetheless, let's start with some measures/indicators:
distributed vs non-distributed, the former being harder of course.
Estimated Kolmogorov Complexity.
Where it (program/concept/data structure/ algorithm) lies on the abstraction spectrum. At one end, we have the lowest level machine code, and at the highest level of abstraction, in my opinion, are advanced typed languages like mathematical theorem provers. Both ends are harder than concepts that lie in the middle of the spectrum.
Number of collaborators ? Higher is obviously better
(Lines of code included indirectly in KC)
Seems about it. LLMs provide some more, but all of those can be derived from the above points.