Google Site Reliability Engineer interview questions

Was contacted by email by HR. Didn't ask how they found me but I guess its because of my candidate account in their job website + a lecture they gave in my University in which CV were requested for registration. I started the process and halted in the beginning since I didn't have enough time to prepare. At first there was a general conversation about my willing to relocate to another country and it seemed they put effort in making sure you understand that SRE is different than a regular SW eng. (send you many video and blog links about what is the job). The second step was a technical talk with the HR representative with general programming and data structure questions, they were pretty much identical to what I read on Glassdoor before. Although they weren't so hard. The next step was suppose to be a serious technical phone talk with an engineer but I postponed it because I am currently busy. They said its not a problem and we could continue the process in a few months. The thing that caused me to postpone is the list of study material they sent me for the interview. It was long and included books and online courses. I realized I won't have time to prepare for this a kind of thing shortly.