Rule #1, know going in that they know what your salary requirement is. Ask them many times throughout the process, if they flinch at any point drop them. Then continue on with your interviews. If you're asked to go in for an interview more than a few times, it's a major red flag. There is zero reason for this. They can do background checks on you. They can ask for references to people you worked with etc. Don't be led on. At this point, you're time is worth more than theirs because this process drains you mentally & physically, and likely drains your vacation time / pay, so it's literally costing you $$$$ when you interview at new companies.