Hr initiasl tele phonic interview followed ec by technical 3 rounds by diff erent people All not on same day, were a day or more gaps some werfre basic past experiences why you want to join, what is your notice period salary expectations

Recruiter reach out to me in LinkedIn and then arrange the phone interview. The phone interview was with a VP but someone else called me during the phone interview. The discussion was mainly on whatever in my resume. In this 21st century, I can't believe there are companies who are still language agnostics. I mention my primary language is C# but I do work with Java as well, and the interviewer got disappointed. He said they are looking for purely Oracle related technologies. That's means you don't allow your employees to try out new technology or don't give the option to learn new things. What are the challenges moving from C# to Java?