I live in Rumeli Hisarüstü, flat is about 3 mins walking distance from the South campus, North campus and metro station.
Their flat is 3+1 and fully furnished. The room has two windows (one opening to the balcony) so it is quite bright
Pırıl was really great and flexible about hosting my sister when she needed a place to stay last minute and I didn't want her staying in the hostels near Taksim/Istiklal. Her room is clean, plenty of outlets, and located super close to Bogazici. Initially, I didn't clarify that I wouldn't be staying which I think was confusing, but Pırıl was kind enough to have prepared two places to sleep (a mattress and a bed) anyways. Her roommates were also super chill and offered coffee, food, etc. I would recommend her place if you want to be in a quieter part of Istanbul that is still close to public transportation!