While it's not solely the responsibility of the programmer, most of the responsibility should fall on the programmer. It's a much more efficient system for the

While it's not solely the responsibility of the programmer, most of the responsibility should fall on the programmer. It's a much more efficient system for the programmer to own UI/UX and for testing and QA to simply verify. In contrast the the programmer doing whatever, and leaving the full responsibility of UI/UX to the testing & QA cycle.