It's been an experience worth of a try, but in this experience of mine, nothing has been perfect from the beginning... for instance: the first interview has been described just as an "informal chat", while instead at the end of the interview the recruiter asked me 4 (not difficult) technical questions. There is nothing wrong about that, on the contrary I approve it, but since it was told me "just an informal chat" the recruiter could have at least specify "with few technical questions to check whether you can fit for this role".
The coordination for the phone screen interview, has been the worst thing I've ever seen since I started my job in IT, I've been rescheduled 4 times, one of those rescheduling had a 30 minutes notice, so I went back home and I took a half day off for nothing!
After such a struggle I passed the phone screen, it was an average interview (HTTP, TCP, IP Troubleshooting, Linux Bash , coding question and a bit of system design), not difficut, but still challenging.
Then I had 2 technical on site interviews, and there, on the second on site interview, my experience with Google ended. In coaching session and in preparation video they told and repeated, "We appreciate if you have the best solution for the problem, but if you write an ugly solution that works, and you are able to discuss O complexity, and then in follow up question you try to improve the solution, that's fine for us". It's wrong: I wrote a working solution with actual code in my prefered language, I discussed complexity (O(N^2)) but since I had few time left I wasn't able to suggest a more optimised solution for that problem, therefore I failed that interview. So yes, REMEMBER THIS: For Google coding interview, solving the problem with a brute force solution and discuss the complexity is not enought to pass the interview. And that's true even if you're applied for a role that doesn't strictly require coding.