Grant Steuart

Instead of having the user copy and paste the CSS directly, have them copy and paste the HTML that will include an external CSS file generated and hosted by your application. This will allow you to control when the stylesheet is updated as well as control privileges on who can request the file. Additionally, using a CDN service (e.g. Cloudflare) will allow you to cache the static assets being requested reducing overall server load.

When your server (and optionally CDN) no longer are serving the file, consider the link expired. Unique URLs can be generated using a multitude of methods but maybe consider if there is any benefit to the users if it follows the scheme: yourdomain.com/USERNAME/CUSTOM_NAME.css rather than something like: yourdomain.com/style/SOME-UNIQUE-HASH-1234.css

• Server rendered HTML output from PHP is being migrated to the client as Vue.js components, future plans to provide additional content, and other new miscellaneous features all result in a substantial increase of static files needing to be served from the server. NGINX has better performance than Apache for serving static content.
• The change to NGINX will require switching from PHP to PHP-FPM resulting in a distributed architecture with a higher complexity configuration, but this is outweighed by PHP-FPM being faster than PHP for processing requests.
• The NGINX + PHP-FPM setup now allows for horizontally scaling of resources rather vertically scaling the previously combined Apache + PHP resources.
• PHP shell tasks can now efficiently be decoupled from the application reducing main application footprint and allow for scaling of tasks on an individual basis.