In a company like Google or Facebook, it may not matter whether or not you have any experience with technology X, because they have a large training organization that will teach you proprietary technology Y anyway. Their interview process might therefore come across as overly academic, because there's a good chance you might have to "study" and quickly learn something arbitrary as part of the job.
In a much smaller organization, it's unlikely that you will encounter any technology or basic problems that haven't been seen before and it's much more important that you have a baseline level of competence in your expected job. It's also less likely that they have an organization dedicated to training software engineers.
Logically, these very different types of companies should have very different interview processes, but that isn't always the case.