The exercises are so beautiful.
I loved the detailed and stellar presentation of rest and spread operator - many nuances became much clear especially since I come from python where the syntax and the behaviours are a bit different.
May I suggest that you add object destructuring also in the lessons as only array destructuring is covered now? The syntax of specifying only a few elements when destructuring array especially in function params can be also explained more explicitly as this knowledge is expected in the exercise. I learnt quite a bit after submitting my solution by reading the solution of @SleeplessByte - would suggest that some of his ideas are brought up to the explanatory article. If needed, I can do some edits and submit a PR>