That's called a second dishwasher: one is for taking out, the other for putting in. When the latter is full, turn it on, dirty dishes wait outside until the cycle finishes, when the dishwashers switch roles.

Hmm, that doesn't match my experience. It takes me a lot more time to put dishes into the dishwasher, because it has different places for cutlery, bowls, dishes, and so on, and of course the existing structure never matches my bowls' size perfectly so I have to play tetris or run it with only 2/3 filled (which will cause me to waste more time as I have to do dishes again sooner).

And that's before we get to bits of sticky rice left on bowls, which somehow dishwashers never scrape off clean. YMMV.