This is not a thing. Everyone goes through the same level-adjusted loop.
> Another way is to be a significant contributor to some popular open source project.
LOL no. Google is literally famous for rejecting major open source contributors for not knowing how to reverse a binary tree.
AFAIK, you could swap the child pointers and do that recursively for the child nodes. You could also do things O(1) by just changing the comparison function, perhaps by wrapping it to negate the comparison.
They probably didn't want Brew author that much; we don't know the details.
As for popular open-source projects, I don't know about Guido van Rossum or Rob Pike, but Max Howell definitely whiteboarded in his interview: https://twitter.com/mxcl/status/608682016205344768
I have a very solid network inside google (ex-coworkers from another FAANG job) and also from xooglers, at IC and management track.
Even in my last interview failure (see my post here), the recruiter told me I had more than enough to support my application. Yet, an exec made the no-go call.