I did some bra research when Deb was complaining about how shopping for bras totally sucks.

There are (from what I found) multiple measurements involved in a bra, some of which cannot be done with a tape measure. Such as breast volume—which is not the cup size, apparently, in which case what is the cup size supposed to measure? — and breast shape, which (obviously) changes due to age, pregnancy, post-pregnancy, menopause, and weight change (there are probably other factors I've forgotten, this was a few years ago).

There are places that will take all these measurements, perform some algorithmic magic, and deliver a bespoke bra that fits perfectly. Or not. Sometimes not. Often not, apparently. 🙄

We have damn good female engineers in this world, why have none of them come up with a decent methodology for getting decent-fitting bras on women?