I don't have personal experience, but from what I gather they work their employees to the bone. Everybody in there is expected to do all the jobs at a fast pace. The cashiers are expected to work incredibly fast, and if the register is slow, they close it down even for a couple of minutes and have the employees do something else. Pay (in Germany) is above average for cashiers, but there's been some serious union-busting fuckery at Aldi and Lidl that's actually quite shocking by German standards. Lidl (maybe Aldi as well?) are surprisingly in favor of a higher minimum wage, because they need less workers than the competition thanks to labor-saving procedures, and that would give them a competitive edge. It sounds alienating as fuck.