Oracle Principle SDE

I interviewed for a Principle Software Engineer position at Oracle OCI. The interview process consisted of six rounds, two of which were supposed to be coding rounds, two system design rounds, and two rounds with the hiring manager and behavioral questions. However, all six rounds turned out to be system design rounds, even the screening round. The interviewers, who were from the microservices team, were assigned to evaluate my system design skills in big data, despite their lack of experience in that area. The position was for big data, but the questions focused on microservices, which was confusing. In one round, the interviewer kept changing the requirements every 10 minutes. I had to ask him to finalize the requirements, which seemed to frustrate him. Oracle should consider providing their engineers with training on conducting interviews.