Astellas Senior Software Engineer interview questions

First round was basic HR round, he told the next interview will be scheduled within a week, but I got an email after 3 weeks. Second round was like managerial/ technical, the questions he asked was not at all matching the job description, the interviewer was from a completely different tech stack and there are things that are not possible to do in the tech stack that I was giving interview for, he used to compare it to some other tech stack and ask questions, for which there is no solution. Got rejection in this round.