Yes, we are always wondering how it is possible. But you need to understand that telegram rolled not only their own crypto, but their own DB, PHP compiler and so on. Everything is written in C++.
To solve one of the earliest DDOS attacks telegram's team take their servers put it on the track and install them to other DC. This is insane.
To solve one of the earliest DDOS attacks telegram's team take their servers put it on the track and install them to other DC. This is insane.