I'm a netflix watcher, so I'm a season behind (no spoilers please).
However, I can say that their is an easter egg in every episode. If you notice the logo at the end of each episode is a tarot card (the sun). Each episode is one of the tarot cards in the major arcana suit. Not only does the theme of the episode reflect the symbols of the card, but the actual card itself is shown through motifs in the script and (sometimes) actual demonstrations on camera. I've looked online, but no one seems to have picked up on this yet. There are 24 cards in the suit, and by the final episode each card will have been rotated 5 times (it's the reason why the first seasonal episodes are longer).