Amazon Robotics interview questions

Four months and three interviews with few technical questions (that I answered considering the state of the art and my 10 years experience in robotics, while the interviewer was an expert in signal processing and not motivated at all), no coding, to tell me that I am not suitable for the position. I have lost 3 hours of my time. I will not apply again for Amazon robotics, the company seems chaotic and not well organized.