As you correctly pointed out "P v NP is completely unrelated to this thread" so I'm not sure why you decided to elaborate on it. However, seeing as you did I s

As you correctly pointed out "P v NP is completely unrelated to this thread" so I'm not sure why you decided to elaborate on it. However, seeing as you did I should point out that I did not trivialise it, I mention it juxtaposed to the topic in an oxymoronic context which highlights the point I was making (you know, the one you said you understood). To reiterate "It is impossible to tell if a developer is "good" from a short video of them talking..." Last time I checked Math and Psychology were the foundations of Computer Science, and Software Development was very closely related to Computer Science. One might even suggest you needed one to perform the other.