Throughout the interview with Google, you will be asked a series of technical questions about the tools, methodologies, and processes you use in this job. You are expected to have a deep understanding of some of these and be familiar with others. Since observability is a fundamental practice used by a site reliability engineer, you should have extensive knowledge about this and be able to talk about what contributes to effective observability. As with any technical question, keep your answer brief and to the point and anticipate a follow-up question from the Google interviewer.