Favorite place to stay in Istanbul, me and my wife have been to the city 5 times and this was our favorite Airbnb.
Spacious & really nice decorated, with an artistic vibe and homey feel to it.
We also needed to work remote for a few days and the internet was fast and reliable (which I cant't say about other stays we had in the city).
Also, there is a nice small terrace where you could welcome a few friendly cats if you want, if not they seem to keep their distance.
The great location, cleanliness and easy communication with Rana are also things that are worth appreciating.
Rana's recommendation proved very useful, I'd only add Van Kahvalti Evi (for breakfast), Old java (for coffee), Altin sis Salonu (for a quick snack).