Rakuten Software Engineer(Java Developer) interview questions

It took two weeks through agency. After CV check they asked for skype interview. Mostly questions were about oop concepts like basic principals of oops. difference between abstract& interface, Overloading and overriding, experience of writing REST ful api, using inversion control tool, test driven developmnet, agile programming, design patterns and a bit about what is my design strategy. and what I bring to the company..