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...