deep magic

n. [poss. from C. S. Lewis's Narnia books] An awesomely arcane technique
central to a program or system, esp. one neither generally published nor
available to hackers at large (compare black art ); one that could only have
been composed by a true wizard. Compiler optimization techniques and many
aspects of OS design used to be deep magic ; many techniques in
cryptography, signal processing, graphics, and AI still are. Compare heavy
wizardry. Esp.: found in comments of the form Deep magic begins here....
Compare voodoo programming.

