How to configure React app architecture to support localization? 

To configure your React app architecture to support localization, the first step is to organize your project structure in a way that separates code and translations. This is the key to good localization.

Create a folder for translations, for example, "lang", and group your translations by language in separate files. For example, you could have "en.json" for English, "de.json" for German, and so on. This way, feature changes, such as adding new translations, updating existing ones, or removing translations, are easier to manage with a well-organized project structure.

project-name
|-- lang
|   |-- en.json
|   |-- de.json
|   |-- ...
|-- src
|   |-- App.js
|   |-- index.js
|   |-- ...
|-- ...
|-- package.json
|-- package-lock.json

Most localization libraries have their own way of organizing localization files and codes within the app. It's a good idea to check their documentation to see how they recommend doing it.

Finally, check if you need to track the currently selected language in the URL. This may require some changes in your routing.