We've been staying at Aren's place arch 7-31 and we've really enjoyed our time here.
The flat is great - spacious, minimalistic and it is just beautifully designed. All necessary household appliances are present and as good as new. All you need to feel home is in place here. And important point - internet connection is great, we had no any issues during our stay. So if you come here to combine working and travel, this place is great.
We stayed with two cats (we're crazy people who came to city of cats with our own cats :D ). They had here a scratch point offered to them, which they really liked :)
Aren is a great host who can help you with any questions you have. And we actually didn't have many questions because the place has anything we needed.
I would recommend staying here for you time in Istanbul also due to flat's great location. It is on a very quiet street but just the very next street to it is a lively big street with a lot of supermarkets, various shops, restaurants, street food point, ATMs, bus stops, and just all you might need during your stay.
And M2 line subway station - Şişli-Mecidiyeköy - is about 10 minutes from it. Mecidiyeköy is just one station away from Taksim, two from Galata Tower area, and four to Fatih area.