Not the person you're replying to, but I often use "fractal complexity" to describe problems with a certain character, and I (and I assume this poster as well) mean it in the more precise sense: as Wikipedia puts it, fractals have "detailed structure at arbitrarily small scales". Fractal problems have complexity at every level of resolution; they're tricky in broad strokes, and if you zoom into one area it's internally complex, and if you zoom into any sub-area it's internally complex, and so on, forever.

Most of computing is this way if we're honest about it; the space of possible sub-disciplines of software engineering is nearly infinite, as is every possible subfield thereof, or sub-sub-field, or...

GeneralMayhem captured it pretty well, but yeah: it's complex at every scale. You see some complexity, you zoom in, and you find that the bit you zoomed in on is just as complex!

Our founders are pretty deep domain experts on aws cost management. At this point one of them has pretty much a catch phrase: whenever I say how I think some little aspect of aws billing works, he'll reply with "Let me complicate that for you" and describe 2-3 edge cases where what I thought I knew doesn't quite apply. :)