EPAM Systems Sr Developer interview questions

Attended interview for Senior Java Full Stack Dev. Two techincal rounds, cleared the 1st round - It was on moderate level, interviewer analysed my understanding of my knowledge on Java, Microservices, Threads, Mysql, and the approach I took to solve the problem (2 problems - both I've solved it but couldn't make it efficient and also had minor syntax error) but still I got solved as overall it was good interview. 2nd round - Interview took around 2hr and 5 min though it's scheduled for 1.5 hr. He have covered everything from backend to frontend. It's was like rapid questions and answers, would've asked around 40-45 questions for 1 hr and 45min. Then he has asked to write a REST endpoint along with validation, designing entity with interface and it's relation. I did everything well except 1 question on explaining a creational design pattern and 2 questions, and the validation I did could've been improved a bit. But still I got rejected for SSE but selected for Software Engineer role