Google’s recruiting system is famously brutal. Many workers think it’s failing

This sounds like a really bizarre and very specific question for the interviewer to fixate on, unless it was particularly relevant for the position. Knowing the details of how to best do the redirect doesn't seem relevant for a generalist interview; this is the kind of thing you end up, well, googling when you need to do it. I suppose a kernel developer is supposed to know this though, were you applying for kernel development?

Google gets tons of applicants. The point isn't to prevent qualified applicants from being rejected, it's to prevent unqualified applicants from being hired.

They can do whatever arbitrary, unfair filters they want as long as they still have at least some applicants left, and as long as those people are adequate.

Each time until my last interview cycle, they seemingly assigned me interviewers at random and they were usually a terrible fit. I'm a games/systems programmer, so think C, C++, C#, etc. Console games (PS4), PC games, etc. Never shipped a mobile app, don't have much Linux expertise, don't list them on my resume. Haven't written Java since the J2ME era.

So naturally, I kept getting assigned to interview with people who worked on the Android Play Music app, or people who wrote Linux cloud storage infrastructure (think talking to storage hardware directly, etc) in Python and C. Inevitably, it was impossible for us to have an in-depth technical conversation without a lot of overhead because the disconnect was too big. Sometimes they'd ask me to whiteboard and there was no appropriate language for me to use that we both understood. At the end of each day I came away having had interesting conversations with people but it was consistently a failure of an interview process, so it wasn't a surprise that they never made me an offer. You could tell that this messed up interview process was also an issue for interviewers - I had a couple different interviewers get really combative or frustrated because of the disconnect, in one case borderline abusive.

Then finally a team that really wanted me (the NaCL/WebAssembly team) looked at my interview history and just stacked the deck so that everyone interviewing me was actually qualified to interview me. It was a breeze. Sure, it was challenging like any good interview, but not a complete waste of anyone's time.

While I can't speak to this personally, I also have heard from current/former Googlers that in the past it was extremely hard to hire Linux experts (kernel devs, etc) because they kept giving those people the same garbage screen (let's talk about Java!) and then rejecting them in the same way. Apparently the fix was a special interviewing process for people like that, presumably that's the treatment I got eventually.