Actually I thought the Wavesplatform CEO is called "Sasha Ivanov", since when is he called "Alexander Ivanov"?

In Russia, the name "SASHA" has the same meaning as the name "ALEXANDER".

This name is especially common in Europe where it is used by males and females as a diminutive of Alexander and Alexandra. Despite its popularity in informal usage, the name is rarely recorded on birth certificates in countries such as Russia, Ukraine, the Czech Republic, Poland and Slovakia, as it is considered a diminutive and not a formal name. Exceptions are Serbia, Croatia, Germany and Switzerland.
https://en.wikipedia.org/wiki/Sasha_(name)