Just checked my passport- only two stamps: entering Istanbul and exiting it, nothing between (I mean nothing from the domestic airport), I don't remember passing any customs, just a passport check when you enter Istanbul, then showing it again at the domestic airport before boarding on (or a Turkish ID card, that's what the others did).

Yes, there is a separate (and quite far) small terminal for domestic flights.
And no, as I booked for the transfer flight here ahead, my baggage was transferred to the flight directly, I didn't deal with it in Istanbul at all. Unfortunately they sent it in a different flight by mistake, so I didn't see it in Ankara either lol, but the officers in Ankara Esenboğa airport were very nice and polite. After I described the suitcase and gave them it's key (for a security check) they promised that it will be sent to my hotel room and it really arrived at night to my room.

Thank you for your help

Once in Istanbul my baggage wasn't with my flight either and they also brought it to my hotel there. I wonder what they do if the passenger is going to a place far away.. Hopefully it won't happen this time

Hi all,

I have just come back from Ankara via istanbul.It was fairly easy on the way there when i arrived in istanbul i went to get my visa and then i went through passport control then you should make your way to the domestic terminal (quite a long walk and signs are a little confusing but you can always ask)(dont collect luggage unless told to by the airline)once at the domestic terminal you should check your flight number on the screeens and go to the appropriate gate remembering to go through a security point first (baggage and self scan)once you get to ankara you dont go through any security you just need to collect your luggege which confusingly for me came to the international arrivals baggage claim hall.
Hope this helps.