I messed with scrimba for a bit and it’s nice, but the best js class I’ve come across is JS The Hard Parts on frontend masters. It’s only video though, not interactive.

these are the only exercises you do: csbin.io What I like about that course though is: 1. it feels like a real class, mainly because it's a recording of one 2. everything is focused on the context of the steps the browser is taking/understanding the call stack.