In effect, terminal 2 and 3 are just different banks of checkin desks for the same airside terminal, 2 being the old building. You can see the split between old and new airside too (depending on whether you turn left or right from the exit-through-the-duty-free shop, but by this stage, it's the pier letter that counts, not the terminal.

On arrival, it's a common exit, as noted above. Immigration takes place at the end of the C-pier, for non-Schengen. This is part of the new building (and where several DY flights arrive), but I guess the simplify things by letting the checkin location determine the nominal terminal.