When you arrive at 3AM, you'll have to wait until 5AM in the transfer zone! Before you can reach the departure lobby. In the zone with no seats and no personnel. They will just tell you, that the transit zone will open at 5!!!
It is a very large, beautiful and modern airport. Border control, screening, baggage check-in and collection are well organized. It takes 15-20 minutes to obtain a transit visa. A large variety of shops and cafes. There are several comfortable business halls with quite tasty food and a good selection of drinks. You can get to the city by metro, but it's 7 minutes faster and more interesting by high-speed Maglev Maglev train. It is impossible to get lost. The routing is perfectly organized. There are luggage storage facilities in the arrival and departure halls.