Their questions are 1)Which RDBMS you will choose for large dataset and why 2)Version controlling(Git command to ignore particular file.I mentioned .gitignore that he not considered) 3)Architecture i)API ii)Application 4)Automation of deployment 5)Caching 6)Redis vs memcache 7)How to switch from RDBMS to NoSQL and vice versa etc.
Sigiloso
Through questions like this, interviewers are mostly trying to test your skillset (and its relevance to the role) as robustly as possible, so be prepared for multiple offshoots and followups. It could be a useful exercise to do mocks with friends or colleagues in Rakuten to get a real sense of what the interview is actually like. Alternatively Prepfully has a ton of Rakuten Web Applications Engineer experts who provide mock interviews for a pretty reasonable amount. prepfully.com/practice-interviews