It’s not that hard to do performance profiling even if it appears to be a lost art these days.
And in turn each of those may also appear simple in isolation, but as a whole it can still be an overwhelming amount of knowledge to learn, integrate and connect the dots between (and then once you reach that level of mastery, there's meta-problem of applying outdated rules of thumb from a few decades ago to modern hardware). That's where the advantage of having the kind of lifelong experience like a former demoscener gamedev comes in.
Anyway, my earlier post might have been a bit tongue-in-cheek but I'm rooting for you to surpass this guy one day! :)