It is hard to tell if this is a good design without more information about the application's requirements.
Another thing to consider is that sometimes interviewers will suggest strange designs to see how candidates react. I'll typically do this when I'm hiring for a role that isn't a personal competency of mine, but where I've had experience (usually f'ing things up). My goal is to see if the candidate is any better at solving the problem than me! Bad candidates will slavishly accept my poor solution. Better candidates will immediately suggest a better solution. Best candidates will compare and contrast my weak solution with their better solution and explore when each option makes sense.
I would guess that the Java front end was selected for portability reasons. I would argue for a browser-based interface to accomplish those same goals, but maybe their UI/UX people really loved Java.