Overall duration:
The process lasted for around 4-5 months - from the date I applied to the date I received the offer (this long time was owning to the month of December (holidays season) and also extra preparation time I had asked for and delay from Google's end).
Initial Discussions:
My initial interactions were with Google Recruiters for Initial Screening/Interview process sessions.
Round #1 and #2
Both rounds were focused around data solution/dwh design questions, data modelling, system design questions around data platforms, SQL problems and simple coding. In both the round I found the interviewers had great patience to listen to the approaches and discuss the solutions and cover the pros and cons of the suggested solutions. I did good in both the rounds.
Round #3/3.x
This round was standard coding and system design round. I did not did great in this round and I was asked to appear once more for this round - and was given around 4 weeks time to prepare. I took additional week and then appeared for this around. The interviewer I met was cooperative and had patience to listen to the solutions I proposed and did discussed in details about pros and cons of solutions.
I was asked one coding question and one system design question. I was able to clear this round and had a great relaxing feeling after this round.
Round #4
This was the Hiring manager and Googliness round. The hiring manager listened to me with patience and gave me different situations and learned about my reaction/solutions to those situations.
Yes, I was able to clear this round.
Finally
This was it. I was all set and received the offer from Google Cloud Professional Services. I was excited and felt great. It was like dream come true - getting an offer from Google.
Summary
Overall I had a great experience in interacting with Google Recruiters and Engineers. Interview process was definitely long and could have been shorter (though I agree I myself asked for extra time to prepare for coding round). Most of the recruiters I met were cooperative and had patience.
p.s - I did not joined Google and turned down the offer later [that's another story :( ]