He's not that old, but he's not that young, either. He worked on Plan 9 for like a decade before this happened. A few years before he put out this blog post, he finished his PhD thesis. While a bit silly to hire someone with that much experience as an intern, it is how most PhDs are treated.
I was actually thinking of Alan Cox!
Alan Cox is in his fifties!
Try to imagine my shock and dismay when, after working with Russ for a few years, I discovered that we were the same age.