Another great course I'd recommend is Big History. Like nand2tetris,it gives you a great overview of the entire history of our being. From Big Bang to 2018.
Also, I am looking for some great online courses on Distributed systems. It would be good if assignments are challenging and where you have to write a lot of code.
 Nand2tetris: https://www.coursera.org/learn/build-a-computer
 My Nand2tetris journey in tweets: https://twitter.com/abiduzz420/status/1076192382398357505
 Big History Project: https://polymathgoodies.xyz/big-history-project/
Edit: added extra spaces