Mark Vasilkov is a software craftsman—or engineer—whichever you prefer. He specializes in Python and JavaScript development, mostly related to web and mobile applications, and has 10 years of experience in hacking stuff together so that it mostly works.

For what it's worth, Mark is a Russian Israeli. This very book was partially written in a bomb shelter due to Hamas shooting long-range rockets (containing warheads with up to 200 kg explosives each) at Tel Aviv. Israel is a beautiful country, inspiring everyone in the region to do something truly remarkable and idiosyncratic.