5 rounds: recruiter phone screen, hiring manager interview, interview with potential teammates, panel with other engineering managers, and then final interview with CTO and hiring manager. Mainly culture fit and conceptual knowledge questions. There was a few questions about Python specific knowledge and debugging APIs during the teammate interview. The first four interviews all went well, I had good reception and rapport with each person. The recruiter was very prompt about scheduling the next round each time. I was rejected after meeting the CTO. At the beginning of the interview process, I had been told that this was mainly a culture fit round, but the CTO dug in to my resume. He was not happy that I didn't have perfectly matching experience with the volume and type of data ingestion that the team handled. I received a rejection notice two days later.