So far, the best place I've stayed in Istanbul!
I can totally recommend this apartment for a digital nomad. Fast fiber internet (most of the places in the area still have ADSL connection). The table is comfortable, but if you feel more social - there's a coworking across the street.
Apartment is in the new building, everything is brand new from what I can see. Warm floor in every room so you won't get cold in the winter.
Nice park in just 2 minutes from home. The area and building itself are quiet (I've lived in 4 different neighborhoods, and Beskitas is the most livable one). Many great restaurants and shops.
I'm going to stay at Eren's place again for sure whenever I'm back in Istanbul.