The interviewer was kind and flexible in scheduling. There are 4 rounds of interview + a challenge question. The first interview went well but a response for the challenge wasn't sent out until I reminded them. After the challenge, there was a negative response without any explanation which really upset me as I liked the role and was looking forward to the next interview with the engineers but they did not bother to return even any feedback on what lacked. I was given a response related to experience when I asked for feedback, which should have been clarified in the first place when they looked at my profile.. I know they want the best for their company but they'll lose people who can actually provide to the company and are excited about the technology!