In addition to precise temperature control, the ripening process also depends on atmospheric design. Over a 24-hour period, each roomful of bananas is gassed with ethylene, a plant hormone that accelerates ripening (and is also, curiously, the most produced organic compound in the world).
I learned about the role of ethylene a few years back, after wanting to ripen some bananas quickly and being told that putting them in a paper bag would do the trick. I did a test with one banana in the bag and one outside as a control, and the one in the bag did indeed ripen faster. And the internet told me that it was the ethylene that did the ripening, which is why “one bad apple ruins the lot” — as fruit like bananas and apples ripen, they give off ethylene, and that accelerates through the process, so one ripe piece cause the others to ripen pretty quickly. The paper bag concentrates the gas relative to it being out in the open and causes more ripening. Curiously, a plastic bag did not work — this could be because humidity inhibits ripening, and it’s possible the permeability of the paper bag allows water vapor to escape but still retain some ethylene to do its magic chemistry.