title: Webpack taking ages to load page AFTER build is complete
body: <p>We're using <code>create-react-app</code> (with <code>react-app-rewired</code>) on a very large monolith. We've done some improvements to the build time (got it down to approx 20s), but <strong>after</strong> the build is complete (following a <code>yarn start</code>) the application takes a good 2 minutes to actually load on the browser.</p>
  <p>In <code>app.jsx</code> I've tried removing all the root code and just rendered a typical &quot;Hello World&quot; <code>p</code> tag and it doesn't take nearly as long. I've also ran a basic web server infront of the build folder using <a href="https://github.com/vercel/serve" rel="noreferrer">serve</a> which suggests it might <code>webpack-dev-server</code> that is having issues with the size of the application (Or could it be saying it's built before it actually is?).</p>
  <p>In the chrome dev tools network tab the assets that are blocking the page from loading are the files from the <code>static</code>/<code>js</code> folder.</p>
  <p><a href="https://gist.github.com/dexc/49ac1ba47759798f52f1be1ce631ab9c" rel="noreferrer">Here</a> is a gist of the result from <code>webpack-bundle-analyzer</code></p>
  <p>Does anyone have any ideas where this issue could be originating and how to improve post-build load time?</p>