Reading the blog I would say he hasn't been working in a true engineering position for a very long time, probably some sort of engineering manager.
(OP here)
Yeah, I was in a role where I was full time managing for the second half of my Google tenure. Hence the rusty coding skills.
Yes, this also means I'm ridiculing myself on the whole OKR framing thing.
Can we agree how screwed up our joke interview culture is when a Google engineer with 10 years experience has to brush up interview skills? Come on.