Kiev Borispol's website mentions that there if free Wi-Fi throughout the terminals. How fast and reliable is this free Wi-Fi?
The Wi-Fi was surprisingly fast (6/6 Mbps, SpeedTest image below) and accessible reliably throughout the whole terminal.
In 2017 it has also been comparably fast and reliable, with my friend reporting a 10 Mbps Speedtest.
Its a bit hit and miss depending on where you sit. Sometimes it perfect, sometimes I have to reconnect every 2 minutes.