tl;dr:"I'm essentially a believer in You Aren't Gonna Need It — the principle that you should add features to your software — including generality and abstraction — when it becomes clear that you need them, and not before." Luke points to exceptions to the rule, discussing: (1) Applications of zero one many, (2) Versioning, (3) Logging. And more.
tl;dr:"Cypto-mania is not really about technology. If you want to understand what is going on, you need to understand it at the level of economics, culture and human nature." Luke asks the following 3 questions to evaluate cryptocurrencies: what problem does this try to solve? Does it actually solve it? What costs does it bring with it?