I have an ionic app with angular and a backend with spring boot (rest).

The app needs the backend for all of its features (login, data fetching, ...) so it can not operate without its backend.

Now I imagine: The app is live and I have to update the backend for some reason. (scheduled or may be unscheduled (emergency updates)... After updating I would like to test the backend before enabling it for the users. How can I react to thous situations in ionic? Especially when the backend is available but should not be used until I have verified it.

I thought about the following solution: I place a text file on the marketing-website of the app: "live.txt" An the content of the file is either "true" or "false"... ;-) But is this a good solution?

How would you solve this?