EPAM Systems Lead Software Developer interview questions

Total time waste, and highly unprofessional behavior. The process started with initial discussion with TA/HR. Then was first technical round for 1.5 hours which included my experiences so far, project details, Python questions, advanced concepts of AI, ML, Python and Cloud. Then was live coding - design LRU cache; recursive function problem. Then I was scheduled after two weeks for the managerial round. However, in that round also they asked full technical questions and did a live coding again (Que- design singleton class; sliding window problem). This round also lasted 1.5 hours. After 1 week, I was informed that I cleared second round also, and was scheduled for third round (supposed to be managerial). This was rescheduled twice due to managers unavailability and then abruptly cancelled third time. Now that HR is not responding to my calls, emails and messages.