I think the usual approach is to proxy the other domain (or subdomain) to a path on your user-facing domain. E.g. if mysite.com is making requests to api.mysite.com, you would proxy api.mysite.com to mysite.com/api.
I'm building a pure backend service that I want app developers to be able to consume. If they have a static app, they shouldn't be required to run their own backend just to get around CORS. At the very least you're adding an extra hop, which is going to increase latency.
That said, it would be cool if static hosting services like S3 offered CORS proxies for uses like this. I wonder if that's a thing.
That said, it would be cool if static hosting services like S3 offered CORS proxies for uses like this. I wonder if that's a thing.