Can you make a video showing how to deploy an expo app that uses nodejs for the backend and the mongodb database. So the backend has its own folder different from the frontend of the App. The backend is started by running npm start, the app's backend starts and the frontend is started by running expo start. How does one then ensure that when the app is deployed wherever it's deployed away from the local host, that when the deploying service starts the app by running both npm start and expo start for the app to run. What I have seen before is merely people deploying basic apps with no backend which is easy because the hosting/deployment provider will only have to run expo start and the app's frontend starts. But how does the system know that my app uses a different folder as a backend and which needs to be run too when the app must start?