I'm trying to ask this question in the same vein as the various "what is the point of X field" that appear often on this site.
I've just finished a first course in Galois theory. Results that are often proved in a first course (indeed, including mine) include ancient problems such as squaring the circle, doubling the cube, trisecting the angle are impossible, and the insolvability of the quintic.
But other than that, what applications are there to Galois theory? What other areas of mathematics tend to rely heavily on the technology developed in Galois theory?