Would you find an opt-in coding challenge system like StackQuest engaging? Why or why not?
I'm busy enough with life and have my own personal projects to work on. Making challenges that get people to learn new things sounds fun though- kind of like Mario Maker but for programming. I like puzzles and abusing technology for fun. But even if that's engaging, why would people who want this go to StackQuest when there are already existing platforms out there? How will this be different and better?
What types of challenges would you like to see?
The Code Golf and Puzzling model of letting people submit challenges and people vote on them is interesting.
What concerns or improvements should we consider to ensure this enhances the site rather than distracting from its core purpose?
How much interest is this going to get? (considering existing alternatives/"competition"). How much bandwidth do you have to make this work?... and actually succeed in the way you want it to.