Welcome to the discussion thread about this lecture section. Here you can feel free to discuss the topic at hand and ask questions.
Regarding Proxy Contracts, THIS is exactly what I was trying to get at in the ETH 201 course when I was talking about dependency injection. A proxy is a different way of accomplishing the same thing. External contract calls are rather expensive on gas though, so I’d imagine this is used sparingly.
It also occurs to me the increased risk with smart contract programming is in a way a good thing. This forces developers to adopt much better habits. Testing and security are top priorities, so must be considered right from the beginning. This makes better developers.