The interviewer was very respectful and assessed my knowledge about distributed systems, cloud, and deployment tools.
I was being asked about a challenging project I worked in the past. I think this kind of question is highly expectable.
I highly appreciate being challenged regarding my technical background as well as my thought process. My expectation was going through an actual, real-world like scenario. I'm happy being asked questions about stuff that I will actually work on, but I was challenged with some obscure data structure problems, which frankly says nothing about how I work.
For example, I couldn't showcase my knowledge about the development and deployment of machine learning models at scale. This is super important and there are not many people in the industry with real experience.
Perhaps this is the way Twilio conducts interviews, with all due respect, I couldn't disagree more.