Tech Stack for ionic mobile/web app

I’m looking for advice on the full stack of technology for our app. Here is what I’ve got in mind but I’m deliberating on firebase vs. AWS AppSync

I want to use GraphQL and AWS has built a nice GraphQL service in that stack so I’m persuaded but my experience is that AWS is so complicated that I’ve been wanting to use Google cloud services and firebase.

And should I go with dynamoDB vs. RDS? My app will be a high transaction app between consumers so speed/performance will matter.

@aaronksaunders I’ve seen that you have answered several of the AppSync related questions in the forum. Would you mind offering your thoughts?