The job mainly related to Java development, tending towards mobile devices, in the Partner Solutions Organisation (PSO) of Google.
Was contacted about two months after I applied via the online process by a recruiter.
After returning a questionnaire listing where and why I want to work for Google, as well as rating my technical skills out of ten in a range of categories, I was contacted again for a phone interview.
A phone interview was set up, at a date and time of my choice, with someone in PSO. That was meant to last about 30-45 minutes, but was around 50 minutes. It was entirely technical questions: computing theory, algorithms, a bit of maths, general problem-solving. We then spent some time discussing the role and the day-to-day routine.
Within a few days, another phone interview had been scheduled. This one, with an Applications Engineer, lasted an hour. Same format as before.. Java intricacies, puzzles, recursion, followed by plenty of time for questions about the job, environment etc.
Within a week, I was invited to an on-site interview day -- again on a date of my choosing. I was also told that they'd want a copy of my university transcripts at some point (if successful on the day).
The interview day consisted of around six or seven hours on-site, starting with a quick tour then a one-hour written technical test (though I was offered some Google food beforehand). This was followed by five back-to-back interviews of about 45 minutes each. Again, everything was purely technical; there was no "what is your greatest weakness"-type questions. Topics included refactoring some C++, networking, UNIX questions, writing code, algorithms, security issues, mobile devices, more puzzles. At each point, I was able to ask plenty of questions; everyone was pretty open. Everyone I was interviewed by was a developer, as far as I recall.
The recruiters were very helpful throughout, always trying to ensure I had all the information I needed and, as stated, always let me choose times and dates convenient to me.
I wasn't successful in the end (poor final interview, mainly), but was quite irritated afterwards by Google not providing any feedback when I requested it -- especially after so much time invested. They stated it was company policy due to Google being a global company and they didn't provide any feedback to ensure that they didn't "contravene any local laws" due to each country having "different legal regulations" regarding feedback. Annoying as I was a UK citizen applying for a UK job at Google's UK HQ.
Overall, it was a good process -- the recruiters were great, the interviewing style was relaxed and, if you know your stuff, it should be relatively straightforward for you.