Tell us about yourself (professionally). What technical leadership experience do you have already?
Minitest cause its small and light and built into Ruby. That said, Rspec's nice too.
What languages/frameworks do you program in (Java, .NET, PHP, Ruby, etc.)? What is your favorite, if different?
What topics might you be interested in?
Machine Learning, what to look for in a CTO ;)
Do you have any specific areas of expertise? Would you be willing to share it with the group?
Design and Marketing. Sure, ask away.
What is your favorite version control system and why?
Git- cause of its speed, flexibility, and of course, Github.