Optum Data Scientist interview questions

4 Rounds. 1 Long technical, 2 short technical, 1 Managerial. Technical rounds were easy. Questions on basic linear algebra like multi-collinearity, logistic regression, regularization, etc. But the process was bad. I came at 9 AM but I had to wait for 2 hours before 1st round. Then they told me to wait for next round. Soon, round 2 started. I cleared it and they told me to wait for next round. After 4 hours of long wait I had to remind them that I cleared 1st and 2nd rounds and was waiting for next round. Then they casually arranged for next round. Cleared it. Then came final round where some person who was packing things up to leave for the day. But the attendant told him to interview me. He casually took the interview and withing 10 minutes interview was over like a formality. No feedback was given.