Improvement for notification, alert sound, and location update to an Android app.

Hi, I have an Android app for food delivery service that needs improvement for its foreground service. It currently receives google firebase notifications that trigger an alert sound. The location update is done by polling an API from the backend. It is implemented foreground service and background service at the same time and does not work reliably. I think moving them all to foreground service might be best, but any suggestion is welcome. I am looking forward to a developer who can improve this. Please provide your hourly rate with a time estimation for the project. Feel free to ask any questions and I am looking forward to working with you.