Migrate an existing app in playstore from java to kotlin

this is more a theoretical question.

I have an app that is already in the playstore. This app has been working since the year 2017, so it has a lot of old libraries. The goal is to migrate it to kotlin. So, what’s more effective to achive this goal:

1. Migrate file by file to kotlin
2. Create a new project with same buil.gradle in order to have the same id application. But at this point have another question, if I create a new app with the same id, package name.. can I generate a signed bundle apk with my old credentials?

I’m not pretty sure how to achive this goal. If there is a better I would really appreciate it you can teach me how.

Thanks!

Answer

The good point with Kotlin is that it can operate together with Java easily. To rewrite the app completely seems like a lot of work which would need an important reason. You can rewrite file by file and this way keep all functionality working.

If you keep the application Id in a new project, you can update your existing app only if you sign it with your old keystore. These are the two factors that identify your app.