Leave your API architecture to me!!! I have a very good amount of experience in API design and development.
I have experience in database design and development for large scale application. I'm have used many PHP frameworks from Slim Framework to Laravel Framework or even in-house frameworks. I can deliver your data in JSON or XML or both! I'll be involved and involve you as well in all stages of the development.
I can even grant you access to my JIRA portal if you have a big project in mind! Get in touch and let's discuss!