I want to share my google experience with you guys. I have interviewed at Google onsite twice in last 2 years. I got reject this time too.
Last time I lacked confidence in me but this time I was confident but my interview did not go well. It was becoming really hard to communicate what I am thinking in virtaul interaction, Coding in Google Doc is a mess. I was really taking a long time in my coding.

All my interviews were coding focused, they want me to write real code rather than just high level idea. So, prepare well in any one langauge.

I did get a strange feedback, that my interview was close but not good enough for my level(L4), it would have been a great fit for L3. So they will like to do again a direct onsite itnerview in 12 months period. I am not sure if this is standard reply or something very specific to me.