Contacted by a recruiter, I first passed a challenging 45-minute phone screen. This was followed by an on-site interview with five interviewers.

It was about:

• 60% algorithm questions
• 30% design questions
• 10% math

Not a single question was asked about my previous experience or knowledge. My feeling is that Google designs its interviews for Computer Science graduate students. Advanced courses or knowledge in algorithms will be far more helpful than 15 years of expertise in your working field to get a job at Google.

Beware that Google will ask random math questions during interviews. I was hit by a tricky algebra question that I had trouble with. I even encountered a calculus question.

Again, this just shows that they're targeting people from academia who still remember all their advanced math.