Had an interview where they told me about their "design challenge." They wanted me to solve for real-life problems with the current version of their app. They wanted me to solve it based off the current design and then make a secondary version of the app that would be my creative choice. I estimated the challenge would have taken 15- 20 hours to complete because it was multiple large changes to their product. I told them that I would do this for a freelance fee since I believed they were targeting new designers and trying to scam designers. It has been around 6 months and their linkedin has not ever had a hired designer. I'll let you put two and two together.