I'm thinking of introducing a new series of notes on Brilliant. The notes will deal with proof based problems.
Everyday I'll post a problem that asks you to prove something and you'll get the chance to solve them, post solutions and join in discussions. I know that coming up with an original problem everyday is really challenging. So, most of the problems I'll post won't be original (and by 'most', I mean 'almost all').
I also wish to see some really good discussions on the notes. One of things that I've noticed on Brilliant is that notes don't get enough comments. Sites like AoPS and MSE usually have better discussions than Brilliant.
I'd love to be proven wrong about this [pun intended :)].
Have fun proving!