I also agree. If his employer coded the first iteration, he may have a better understanding of the problem space and not care if unimportant parts of the back

I also agree. If his employer coded the first iteration, he may have a better understanding of the problem space and not care if unimportant parts of the back end are sloppy. Or he may need to maintain and debug it himself, in which case refactoring is hurting the business and possibly introducing new bugs. Those are all perfectly good reasons for development to happen HIS way. I would be really irritated if I hired someone to HELP me they started refactoring stuff instead of following my lead on what are priorities and teaching me in areas where they felt I was weak. It sounds as if the latent issues here are power and compensation. If it is really about design approaches, try to make the system more modular and take care of building one of the modules from scratch yourself. Your employer is more likely to hand down additional responsibility once you've proven your approach in a restricted area.