Once upon a time, I was part of a software development project that had an Angular-based front-end connected to a Java-based API. The decoupled layer made it possible to reuse the back-end in other spaces, and our Java dev did that cleanly for our mobile Android app ... until that person left the team.
This is a companion discussion topic for the original entry at https://triplebyte.com/blog/how-i-build-a-front-enders-stumble-into-hybrid-mobile-apps