I want to host a scalable blog or application of this sort in nodeJS on AWS making use of AWS technologies. The idea here is to have a small EC2 server that is not responsible for serving the website, but only for running the CMS/admin panel. While these operations could be serverless as well, I think having a dedicated small VM EC2 instance could be more efficient, and works better with existing frameworks, etc.
In my diagram above, you can see there's two type of users audiences and admin/writers. Admin CRUD operations also cause lambda to run. Lambda generates the static site after Admin changes, which is delivered to S3. Users are directed to the static site hosted in S3. Only admins/writers have access to the server-connecting part of the site.
I think this is a good design for an extremely scalable and relatively cheap site, as long as the user-facing side is all static. An alternative to this is a CDN, but then I have to deal with cache invalidation issues, a site that updates slower, and a larger server.
This seems like a win-win to me. Feedback?
This ought to be a comment rather than an answer, but as I don't have enough points...
There are a couple of other considerations for this architecture. Lambda functions are great for scaling out microservices horizontally with each small function being executed in parallel tens or hundreds of times. Generation of a static site is typically a single threaded operation so you may not see the gains you expect, you'll also need to watch the timeout period (maximum 300 seconds currently) and make sure that you can generate the site in that time. Of course if you are not running Lambda code you are not getting charged.
For your admin frontend I would suggest ElasticBeanstalk, even if you peg it at a single instance, it gives you lots of great features like rolling updates.
Good luck with the project.