After you apply you get what seems to be an automatic email with a HackerRank test. Not even a call before? Anyway.. I wasn’t familiar with HR. By the time I decided to use Xcode it was too late. Why not creating a realistic test, using an API of your choice, and build an app with technologies/architecture that the team is using, instead of a random math/algorithm problem, that might have nothing to do with the expected work, and can be researched if needed? I respect their hiring process, but certainly dodged a bullet here.