To achieve this, you can set up a reverse proxy to forward requests from example.com/blog to blog.netlify.app while keeping the URL unchanged in the browser's address bar. Here's how:

1. Create a Worker in Cloudflare and configure it to forward requests to your blog.netlify.app.
2. Set up a route in Cloudflare to direct traffic from example.com/blog to this Worker.
3. Ensure your absolute paths in SolidJS are configured correctly in tsconfig.json so that asset paths resolve properly when served from Netlify.

This setup ensures seamless proxying, and SolidJS's absolute paths should work as long as Netlify serves them correctly. I implemented a similar setup on my website, and you can check it out for more details. https://sonic-happy-hour.us/