Hosting web app on a server and create API to interact with Android app (iOS future)

you can either use the existing routes of the application to serve JSON content instead of HTML (Laravel already handles this very well in response to Ajax requests e.g. if the request headers contain X-Requested-With: XMLHttpRequest)

or

create app exclusive API routes and serve whatever content you need

you have to find ways to ensure the user is authorized for the requests, but it really isn't that much different to your normal web application.

take a look at https://jwt.io/

You can do this by using laravel/passport

https://laravel.com/docs/5.6/passport

I use AWS for hosting

Thank you guys really helpful,

where do you think can be the "bottleneck" in case the website/App will be successful and used by many users?

Famous and very successful and massively used app (Instagram, Facebook, Twitter and so on) how do they manage the fruition of contents from different platform having one single place where they store the data? I would imagine that they use something "a bit" more sophisticated than a simple RESTful API.

Build first, scale later. Most of the optimizations we have planned in our heads at the beginning of a project are unnecessary as those challenges are not mission critical.

I'm not in any way saying you should not follow best practices when building your project but do not focus on scaling when it is not yet a headache for you.

For the API, I would suggest using passport for Authentication and Postman for testing. You could bundle the API and WEB parts of the application into one project and use the different routes\web and routes\api files to differentiate them.

If I were you, I would separate my Controllers based on the part of the application they would serve.

Thank you so much really appreciate your suggestion