I'm currently building something very similar. The stack is very similar to what you're proposing: S3, Route53, Cloudfront, with a Django backend running on L

I'm currently building something very similar. The stack is very similar to what you're proposing: S3, Route53, Cloudfront, with a Django backend running on Lambda (using the great Zappa! framework for this), and a very basic CMS built with React. Django and React apps rely on a Graphql implementation (Graphene + Apollo) for data transfer. For a short while I considered using Google's cloud offering due to S3 having a 50 bucket limit but they have since dropped that limitation. I've been jumping back and forth between the infrastructure and apps solving each problem only when necessary but would be happy to share what little experience I have with you. You can PM me if you like: mail[at]woven.website