There are 2-4 Technical rounds and one HR round, out of which if you somehow end-up in front of the cloud specialist for your first round and you're not great with explaining theoretical subjects, you are doomed! He is not at all interested in any programming or data structure problems, while other interviewers would be asking questions on Pointers, Probability etc. If you're lucky enough to not get the cloud guy for the first round and your sound with the basics, You're hired!