I know it's a luxury that I'm in a position to do this, but anyway: in general I won't continue interviewing with a company that expects me to put in significant effort into just preparing for the interview. Make a full presentation, build a small service or other not-trivial take-home coding challenge, put together a business proposal, etc.: I'm sorry, I don't do any of that for free. My resume and references speak for my abilities, and while I'm happy to have them probed and challenged (heavily!) in an interview context, that doesn't extend to my putting in hours of work just go conduct the interview at all.

This isn't high school, and you're not going to give me homework just for the chance to work for you. And I use the homework analogy intentionally, because just like with school, this doesn't scale. I can't interview at, say, 10+ companies all of whom are expecting me to put in paying-employee-level work just for the interview while also holding down my regular job. And I'm not going to go with a significantly shortened list of candidate companies just because their interview process is so onerous that I literally don't have the time to talk to more.

Again, I know not everyone can do this, but realize that companies try to exploit you during the interview phase, too. You need to also have standards for what you're willing to put up with.