I believe the post had already been filled because the interviewer himself didn't have an idea of what to ask during the interview.

HR had informed it was an LLD interview round, but not a single question was asked about LLD.

Questions covered SQL, API, HLD designing, stack vs. queues, application of stacks, and messaging queues.

At the end, the interviewer asked me what round this was, whether a DSA round or a first technical round.

Within an hour, I received an HR rejection email.

This seems to be just for the sake of showing that an interview was conducted. Please don't do this; it affects our confidence levels.

HLD for Splitwise app.

Questions on transactions and the money owed to each person in group calculation.