I have a visceral hatred of supermarkets. But H Mart is different. I actually like going there. It also seems like a kind of logistic miracle. How do they keep

I have a visceral hatred of supermarkets. But H Mart is different. I actually like going there. It also seems like a kind of logistic miracle. How do they keep such a dizzying variety of stuff on the shelves, such a huge selection of fresh produce, meat, and fish?