Subscriber here, I felt like I needed interview preparation to be able to go through this interview preparation. I think it would be helpful to list some resources for those less well-versed with these types of problems.
The problems are definitely a bit more advanced. I do try to make sure that any "vocab words" (data structures, algorithm types) can be clicked on for a deeper explanation. But if you haven't seen big-o before, for example, you'll be in the dark on a few things right now. I have some more "bottom-up" curriculum that I've developed from teaching at boot camps around San Francisco, and I'm still working on figuring out the best way to present it on the site.
Will you be adding more questions in the future?
I do like the concept of the site!