Scaling ruby apps to 1000 request per minute: Most of us don't have to worry about reaching twitter-scale. 1000 rpm will more than cover us.
Ludicrously Fast Page Loads - A Guide for Full-Stack Devs: A lot of talk about how fast Go, Elixr etc are. But is that really the low hanging fruit for fast web pages?
The Definitive Guide to Object-Oriented JavaScript: A half-hour screencast, extremely well explained.
The Javascript Event Loop: 27mins, a rare level of clarity for a conference talk.