First round coding second round technical HR third round technical HR final round general hr all rounds were cleared and it was a good experience ..I joined there and worked for 5 years

To develop a MVP using their API. 1)To submit an idea which uses their API 2)After that they have seen our ideas and shortlisted. 3)presented our idea im front of them.Just the idea. 4)A final 30 min interview. I was out after the third stage.The bad thing is that they have not even checked our MVP which we developed.