Caching bundled and minified JavaScript and CSS in the free tier on CloudFlare with the ClientDependency package in Umbraco and other IIS-hosted websites, see https://blog.dangl.me/archive/caching-bundled-and-minified-css-and-javascript-with-the-wrong-file-extension-in-the-free-tier-on-cloudflare-with-umbraco/

ClientDependency.config

<mvc defaultRenderer="StandardRenderer">
  <renderers>
    <add name="StandardRenderer" type="Dangl.Blog.NonAxdDependenciesRenderer, Dangl.Blog" />
    <add name="LazyLoadRenderer" type="ClientDependency.Core.FileRegistration.Providers.LazyLoadRenderer, ClientDependency.Core" />
  </renderers>
</mvc>

NonAxdDependenciesRenderer.cs

namespace Dangl.Blog
{
    /// <summary>
    /// This renderer replaces the file extension .axd in the generated bundles for JavaScript and CSS. This
    /// is required because the CloudFlare free tier does not support caching for .axd files. This can only
    /// be used in combination with a rewrite rule that rewrites DependencyHandler.(css|js) to DependencyHandler.axd,
    /// e.g. in the web.config file under system.WebServer/rewrite
    /// </summary>
    public class NonAxdDependenciesRenderer : ClientDependency.Core.FileRegistration.Providers.StandardRenderer
    {
        protected override string RenderSingleCssFile(string css, IDictionary<string, string> htmlAttributes)
        {
            return base.RenderSingleCssFile(css, htmlAttributes).Replace(".axd", ".css");
        }

        protected override string RenderSingleJsFile(string js, IDictionary<string, string> htmlAttributes)
        {
            return base.RenderSingleJsFile(js, htmlAttributes).Replace(".axd", ".js");
        }
    }
}

web.config

<configuration>
  <system.webServer>
    <rewrite>
      <rules>
        <rule name="DependencyHandler">
          <match url="(^DependencyHandler\.)(css|js)(.*)"/>
          <action type="Rewrite" url="{R:1}axd{R:3}"/>
        </rule>
      </rules>
    </rewrite>
  </system.webServer>
</configuration>