Use phone apps to open the entrance gate of the building and the door of the flat. I don't have data in Italy and this really over-complicated the check-in process.
The electronic device on entrance sometimes was not working, and one night I was completely locked inside the building and couldn't get out. If a fire or accident happened I would be in grave danger.
Actually, I would recommend the flat owner to hand over a key or state clearly where it is ( I spent one hour to figure out the gate was impossible to open by electronic devices and then found a key near television).
Moreover, I have found a monitor camera in the kitchen. I don't know exactly the rule or law in Italy if this is allowed but I don't like the feeling of being watched.
Except for that, this place is awesome and is very clean.