I had two rounds before being dropped off. The experience felt very different depending on the interviewer.

The first interviewer was a US national with long experience in distributed systems, and it was a really interesting round.

The second round involved an interviewer who had joined the company six months prior. They seemed indifferent, had no interest in the interview, and didn't want to listen to my answers. They even finished the interview in 40 minutes.

The first round had too many questions regarding distributed systems, so it's not possible to mention everything here. However, the main details were around Apache Hadoop HDFS, specifically how it's built internally. There were also some questions about CAP theorem and how it's achieved in HDFS, along with its internal workings and past experiences.

The second interviewer seemed unprepared. They asked me to implement two wrapper methods around HashMap: one to fetch and one to delete. This was a very basic question, solvable by any computer science student.