I started explaining distributed caching systems. Pre Load and post load caches, client cache, API gateway cache, reverse proxy cache, application cache, cache as a service (Redis). I spoke for about 5 mins and then paused to ask which component would they like me to go in depth. Clearly, they were not aware of any of this. And they came a question which made me burst in laughter in my head. They said, "All this is fine, but have you worked on LRU." Made my mind to never join this company when I heard this. Got really disappointed about wasting my valuable time. That is when I realised that I might not be shortlisted for next round, since they didn't even understand what I was saying.