The recruiter first did some screening by phone, asking a few technical questions and driving me through Google's "self-evaluation" in about 10 domains (networking, *nix internals, *nix sysadmining, algorithms, and various languages) (the recruiter had a good idea of how I *should* score). I was asked to narrow down where I would work. Google picked an interviewer from one of the would-be sites of employment for a coding interview done via phone and a shared document. After that I did a day of interviews at Google's offices. Lunch wasn't an interview but I was also accompanied by a Googler who let me ask questions about the work, office life and such (all interviewers did this, but the interviews rarely left enough time). Sent back feedback to the recruiter, who called me back when the hiring committee declined to make an offer. Unfortunately the recruiter gave very little feedback when asked, claiming it wasn't shared with them.
The on-site interviews featured troubleshooting, coding, large-system design, plus a bonus topic of my choosing (SRE-related) and an extra interview which I think was picked where I ranked highest. My least favourite was the troubleshooting, since there was no actual terminal prompt and I was at the mercy of the interviewer deciding how the system was built, how it would manifest symptoms, and their understanding of how my commands would work. That interviewer had asked me to pick a small number of things to monitor, without deciding what the purpose of the monitoring would be.
Aside from early interaction with the recruiter, and the fact that my interviewers had access to my resume, there was very little of the traditional HR approach to recruiting; this was almost all technical, and I was the only one asking questions about the more general fit.
One annoying thing is that, aside from the recruiter, everyone called me from numbers that wouldn't answer back. This plus the distance made organising some things painful. It also means you have to write down anything you might want to ask in advance, because the people calling you are more prepared than you do.