I have used Zalando for years, buying well-known brands. I have never had any problem finding items, receiving items, or returning items. Everything is great. The site is trustworthy and the customer service has been good when I have needed it. It's not always the cheapest place to shop, but they have some pretty good deals during sales periods where you can get big-name brands at low prices.
They deliver on time as promised. The app itself is very fun to surf and get inspired for new looks. They got amazing deals on some items and the return policy is amazing.
The only thing I'm dragging this down by 1 point is their latest promotions of the lgbtbbq agenda/multigenders