What things do you configure based on different environments? You might have views that are only for debugging, or you might want to turn off logging for release builds. You probably have multiple backend environments to configure like dev, QA, UAT, stage, prod, etc. Each of these requires different root URLs, API keys and app secrets. The app may also integrate with social media, crash reporting tool, or other analytics tools and we shouldn’t pollute this data with our testing efforts. We might also want to change the app icon and app name to make it visible which environment an installed app is running.
It’s easy enough to develop simple iOS apps and not worry too much about configurations. When you are just starting, it’s probably ok to do some setup with code, modifying the values as needed. You might even try commenting/uncommenting lines of code to switch between different configurations. Some people use #if DEBUG. Either of these will become problematic, quickly. It’s error-prone and time-consuming. So, what do we do?