I applied for OA lasting for almost 3.45 min. I asked me multiple probability questions, Zap-N and number logic problems. The Zap-N questions were very similar to IQ testing in a way. The key was to get the answers in time.

Apply on website, test, hr interview, tech interview, final interview rounds, offer (final interview round is a full day of interrogation at their office). HR is mostly why do you want to work here etc.