What should I ask Tobi Lütke?

Yes, I will be doing a Conversation with him.  Here is Wikipedia:

Tobias “Tobi” Lütke (born 1981) MSC is a German/Canadian entrepreneur who is the co-founder and CEO of Shopify, an e-commerce company based in Ottawa, Ontario, Canada. He has been part of the core team of the Ruby on Rails framework and has created open source libraries such as Active Merchant

Born in Koblenz, and he is on the board of directors of Coinbase.  So what should I ask him?