I think it’s something similar to leetcode challenges, or adventofcode or something. I’m not associated with them, so I don’t really know entirely.

Their existing problems are not behind an account wall though. You can go to any of their challenges, for example:

• https://www.codingame.com/training/easy/onboarding
• https://www.codingame.com/ide/puzzle/shadows-of-the-knight-episode-1

Then on top there’s a label “Continue without an account” - and you can just try them out. I assume the challenges for this one will be something similar.

And I thought this site was pretty cool, since they actually have some graphical front-end showing what’s going on, instead of just a code-only parsing kinda thing