Acing the iOS Interview, Episode 3: Build an iOS App to Upload Photos |

System design interviews can be daunting, because there are SO many things you have to do and deliver in a clear way, while also communicating and collaborating with your interviewer. In this interview David and Alok show how to strcutre this conversation to design an iOS app to upload photos.

This is a companion discussion topic for the original entry at

I’m literally shocked that the image FORMAT and SIZE was never brought up. Is it PNG? Is it JPG? Does Aspect Ratio and image density matter? Does this only need to be ‘viewable’ or will they want to ‘print’ this?

CoreData is total over kill for this. You can get the URL to the image from the photo library where it’s stored or store it in a local folder for the app bundle.

There are so many API issues and details it would be WAY better if the interviewer laid out a system, a domain and then asked for concerns and issues.

I’m not a fan of ‘theoretical’ based interviews like this. I’ve met many a developer who can tell me every detail about swimming, explain how to breath and their favorite swimming stroke to use, only to watch them drown the first time they get put in the deep end and realize they only knew ABOUT swimming but hadn’t ever done it.