bottom-up implementation
bottom-up implementation: n. Hackish opposite of the techspeak term
`top-down design'. It is now received wisdom in most
programming cultures that it is best to design from higher levels
of abstraction down to lower, specifying sequences of action in
increasing detail until you get to actual code. Hackers often find
(especially in exploratory designs that cannot be closely
specified in advance) that it works best to *build* things in
the opposite order, by writing and testing a clean set of primitive
operations and then knitting them together.