RethinkingWeb interview questions

This was an on campus opportunity, and I applied through an google form for recruitment. I applied for the Full Stack Developer role and the interviewer was conducting the interviews one by one. He started with tell me about yourself question. He asked my area of interest : Frontend or Backend. I said backend and the development part of frontend (i.e. Non-UI related portion). So, then he started asking me about the backend concepts. I answered the questions except few ones. Also, I lacked confidence while answering, so I knew I was not going to be selected. Also, all the candidates that gave interview before me were asked one coding problem for which I was waiting as it was my main strength, but due to lack of time, they didn't asked me.