EY Java Developer interview questions

I got the call for interview at EY for the position of Java developer at their client location. I got selected and cleared all the rounds they had, but I didn't got the offer letter. There were 4 rounds at the EY office in Bangalore at UBCity. All the rounds were face to face and got over on the same day. About 400+ candidates came for the interview and in the last round only 8-10 candidates remained. Round 1 - It was a Java round where the interviewer asked basic Java questions and few questions related to Spring. Round 2 - It was more of Java microservice round where the interviewer questions related to microservice architecture. Round 3 - All the questions asked in this round were related to Spring and Spring Boot only. Round 4 - This was the last round i.e HR round where salary discussions took place. The HR was a bit arrogant. The entire process took whole day from morning 11am to 7pm. Anyways, after clearing all the rounds also, I didn't received the offer letter. My entire day got wasted.