I interviewed with the AI labs.
Telephone screen: 30 minute conversation with the director of AI labs where he asked me a question on gradient descent and stochastic gradient descent. Nothing too hard, just testing some basic concepts on convergence and dealing with out of memory data.
After this round, I was scheduled for a F2F interview and asked to prepare a brief presentation about my work experience. A date was scheduled and I arrived at their office with the presentation. When I arrived, the HR said that the panel wasn't ready because I had not sent them a brief note about my experience. I travelled 40 km (20 km up and down) in Bangalore traffic for nothing. The interview was rescheduled 2 days later.
On-site experience: I spoke about my work experience for almost 40 minutes. Then, had lunch with the director where he asked me about my background, what interests me, etc. Those were followed by 2 interviews with members of the AI labs team.
First interview (45-min): I was asked basic algo-ds questions, questions on a ranking algorithm that seemed vague; I wasn't sure what knowledge he was trying to test.
Second interview (45-min): Probability/statistics and NLP interview - questions on NLP were basic-intermediate but not hard for someone who has some experience on NLP.
Third interview (45-min): With head of AI labs. Again, testing fit, questions of motivation, background on team and projects etc.
Worst part is: they never even called me to give me the feedback. I even asked them twice over email and call but didn't hear from them. Naturally, I assumed it was a reject. This is what irked me the most! I mean, you make a candidate go through all that and you do not even have the basic courtesy to inform the results!
HUGE waste of my time and energy. Worst interview experience so far! It only speaks of the culture at Amex.