What was the best CS, SE or Math video you watched in 2017?

https://youtu.be/aircAruvnKk

3Blue1Brown’s playlist on neural networks. Like other 3Blue1Brown videos, the visualisations and explanations of the math/concepts are so amazing, they give you the intuition behind the neural networks naturally.

The Stanford EE Computer Systems Colloquium has some worthwhile talks. https://www.youtube.com/playlist?list=PLoROMvodv4rMWw6rRoeSp...

Not from 2017, but Growing a Language

https://www.youtube.com/watch?v=_ahvzDzKdB0