For Data Engineer 1st round below were questions asked.

1. can we have nulls in unique keys?
2. What are the various optimised file systems Distributed file system? [Confused?? Actually the interviewer meant what are different file formats used while writing data in lakehouse, which one is more optimised and why? So please, clarify each and every question]
3. Implement row_number() without using window functions.
4. If the table row says "GOOGLE" then print
   G
   O
   O
   G
   L
   E

The interviewer was very much arrogant as well, he was not at all responding properly for clarifications in each scenario. Please think twice if you really wanna crack amazon!