A nice, small, minimalistic apartment that has everything for one person's stay (I stayed there for a week).
I did not have any issues while working online, the wifi and internet connection was good (I usually also bring the internet cable, and could connect directly to the router when working).
The apartment was clean, kitchen equipped with everything for cooking, and there was a washing machine (also tried it and it works well!), no problems with hot water in the shower.
It is located in the nice neighbourhood, a bit away from the Besiktas center, so it makes it calm during the day/night. There are small parks nearby, which is also always an extra in Istanbul.
The apartment is on the basement/ground floor, and in the afternoons it might get a bit dark in the main room, but switching the light on would solve this for me.
Yagmur was also always very helpful and attentive, and very quick to reply.
Overall - great price/quality/reliability for Istanbul!