Code or designs that trade on a particularly intimate knowledge or experience of a particular operating system or language or complex application interface. Distinguished from deep magic, which trades more on arcane *theoretical* knowledge. Writing device drivers is heavy wizardry; so is interfacing to X (sense 2) without a toolkit. Especially found in source-code comments of the form "Heavy wizardry begins here".
Compare voodoo programming.
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Nearby terms: heat slug « heavy metal « heavyweight « heavy wizardry » Hebbian learning » heisenbug » Helen Keller mode