After spending some time doing the exercise, I've sent them the repository with the working app that met the requirements and beyond, using latest Apple tech + best practices (SwiftUI + Combine). The feedback never came. They said it would be done by the end of that week, never arrived. I had to ask for a feedback from the HR person. Then he said: oh yeah, you didn't pass. You could have used X and Y. That was it. No detailed answer about why the chosen approach was "bad". No specifics about why the code wasn't accepted or didn't meet their expectations. Of course I could have used X or Y. And also W, Z, T, U. It's software development after all. EVERY approach has its pros and cons. That tells me that the developers of the company can't argue reasonably about code/architecture, don't have deeper knowledge on modern iOS development and how SwiftUI / Combine works or they simply don't care. Either way, I would keep distance from the pretentious lads -- if you want to save your precious time.