My impression of that bit was that the author was saying it may look like a senior engineer is a wizard, but actually it's just experience and it's not magic.
> just
Exactly, but also that it's quite often experience you had this morning, not e.g. over the last 5 years, that makes the difference.
A quote which shows you were wrong and the person you were responding to was right. You do know what is meant by "impression" in that sentence?