One PM asked about designing A/B testing, brainstorming how to get users back. One Data Scientist asked SQL query questions, and probed some design considerations in creating A/B tests. One engineer asked me to thoroughly design a staged launch plan including pre-launch A/B testings. He mentioned it's an open question and let me design it freely.
Sigiloso
The last Engineer's interview round was pretty annoying. He said it's an open design question. In the process he often interrupted me and steered the question to some trivial details, which should be 2 or 3 steps later if he follows my stated methodology, or wouldn't be needed at all.