Basically they are posting the same JDs on their homepage for literally >2 years. One of the probable reasons to explain this is, instead of really recruiting people, they try to gather information of the candidates and competing companies.
So back to my interview+ as they are not really recruiting but just looking around, you can feel that they ask questions that try to gather your insights on some industry-related topics, instead of more ordinary interview questions e.g. focusing on your skills and why you want to join them.
Apply if you have plenty of time to spend on a process that will eventually turn you down.