I applied through referral. Few weeks after application, I had my first telephonic conversation with one person from the People's team. I was not expecting it to be a short multiple choice questions technical round, however, I did very well and answered all questions correctly. Next round was a one hour remote technical round with a senior member of the technical staff. Based on my previous experience, most of the questions were on Embedded systems, firmware development, C programming language, and some tools such as CMake and GNU tools.Some basic Cryptography level questions were asked. I was able to answer most of the questions quite well. Third round was another remote, technical interview with 2 principle Engineers and this time questions were more detail oriented. Again the questions were from embedded systems, C, Assembly and Cryptography. Fourth round was with another person from the people's team for who focused on cultural fit and personality.