Was brought in few days after a quick phone screening from the company owner. After a brief chat with him, he brings his employees from different "engineering" departments one by one. One of the employees wanted me to derive a half circle using Calculus. I didn't see how that was even remotely applicable to the job I would be doing for the position which was testing and working on their embedded Linux system. Overall I think 1.5 hour interview could have been reduced to 30 if they didn't decide to bring in people one by one to ask the same questions over and over. After the interview I followed up a week later to see whether the position had been filled and was promptly ghosted by the owner. Would not recommend even for a junior with no experience.