HR scheduled two phone interviews, both of them were either delayed or cancelled. It was the worst experience I've ever had in my life. I was asked only one hard level leetcode question in the first coding interview and I was informed rejected after the absence of my second interviewer. It was completely wasting my time (waiting for the missing interviewer) and I highly doubt the structure of their interview setup (what's the point of judging data science knowledge by a single hard leetcode problem?) They could have hired an SE if that's what they wanted.