There have been two times in my career where I tried, as gently as I could, to offer a better solution when I was being asked in an interview to help the employer do something not in their best interests.
Three-fourths of the job description was standard front-end development. The remaining one-fourth was to make an object-oriented PHP webapp that, on every signal I could discern, nobody could understand. Their basic ask in all of this was to improve code quality in the PHP and make it easier to understand: I was being interviewed in the wake of a junior developer being hired to do the same, and floundering.
I tried to gently make the point that sometimes mechanic's bills can exceed payment on a new car, and talked about what is possible with Python. (I don't want to start a holy war on technologies, but I've found myself personally to be significantly more powerful with new Python and Django than I can achieve in a legacy PHP application .)
Retrospective advice? Anything I should do from here?