I don’t think that anyone is posing as an authority in this thread, so framing this discussion as such is not very useful. In case you missed this, @yuyichao is helping you.
Also, in general, while everything can of course be debated, doing this in a meaningful way requires a lot of background when you want to talk about compiler internals.
Finally, as many have pointed out, compiler internals are orthogonal to understanding (not implementing) scope (which was the original question). You can become a very proficient Julia programmer with a perfect understanding of binding and scope without having a detailed understanding of what happens under the hood (especially since it keeps evolving 
).