With most of this being bandwidth costs, it seems like switching to a host like Digital Ocean would make more sense here. The bandwidth costs are a fraction of Amazon's in comparison.
As for the CDN, switching to something like Cloudflare might make more sense rather than relying on Cloudfront. At the least, there's a "US and EU only" option for edge locations to use which si considerably cheaper than the default option of all edge locations.
I presume you mentioned Cloudflare because of their "unlimited bandwidth". That comes with some constraints as to the use/application: https://www.cloudflare.com/terms.html
It's possible RubyGems.org would be classified under one of the "not really allowed here" terms.
> With most of this being bandwidth costs, it seems like switching to a host like Digital Ocean would make more sense here. The bandwidth costs are a fraction of Amazon's in comparison.
That's just replacing bandwidth costs with build-and-run-your-own-CDN costs.
As for the CDN, switching to something like Cloudflare might make more sense rather than relying on Cloudfront. At the least, there's a "US and EU only" option for edge locations to use which si considerably cheaper than the default option of all edge locations.