Don't you think there is a difference from "knowing how it works" and "reproducing every aspect of it at the level of the state of the art" ?

Also, your example seems flawed if you restrict to a certain product. Can I build a compiler from scratch? Yes. Can I reproduce in a year a compiler with LLVM/GCC performance level? No. Can I build a compiler from scratch in a year from a room if I need to starting mining from metals, building transistors, then building the first assembler and then implementing the compiler? You can imagine the answer.

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esikich 5 hours ago | parent [-]

Not really, at least not in this discussion. An assembly programmer gets logic gates, a C programmer gets assembly, etc etc. And each one can say to the one above "well you don't really get it if you can't bang out some meaningful work". Otherwise idk what we're even talking about here. Having a vague understanding of something isn't "knowing how it works".

	▲	lelanthran 5 hours ago \| parent \| next [-]
		Yeah, but if we use your criteria, people have to invent their own atoms out of individual electrons, protons, neutrons, quarks, etc before you'd admit that "hey, they did build a compiler from scratch". I think a fair bar for "from scratch" is stopping at the point they need an expensive fab process (or how else will they reproduce the workings of semiconductors?)
	▲	hparadiz 5 hours ago \| parent \| prev [-]
		Code: The Hidden Language of Computer Hardware and Software https://www.amazon.com/dp/0137909101 Explains how to build an 8 bit calculator with wires, switches, and light bulbs and then keeps on going.