Clearwater Analytics (CWAN) Software Development Engineer - Entry Level interview questions

I met with Clearwater reps at a school career fair and interviewed with them on campus the next day. They had me complete an online coding challenge within the week after that, and then they emailed me to set up a phone interview with an online coding platform that both the interviewer and myself could see. The interviewer was very polite. I received an email from an HR rep two days later that I was not chosen for the position. I was surprised because I thought the interview went well.