1 files changed, 0 insertions, 44 deletions
diff --git a/doc/development/fe_guide/performance.md b/doc/development/fe_guide/performance.md
index 432e66bee33..5e8581663b6 100644
--- a/doc/development/fe_guide/performance.md
+++ b/doc/development/fe_guide/performance.md
@@ -366,50 +366,6 @@ browser's developer console from any page in GitLab.
   parsed, `DOMContentLoaded` is not needed to bootstrap applications because all
   the DOM nodes are already at our disposal.
 
-- **JavaScript that relies on CSS for calculations should use [`waitForCSSLoaded()`](https://gitlab.com/gitlab-org/gitlab/-/blob/master/app/assets/javascripts/helpers/startup_css_helper.js#L34):**
-  GitLab uses [Startup.css](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/38052)
-  to improve page performance. This can cause issues if JavaScript relies on CSS
-  for calculations. To fix this the JavaScript can be wrapped in the
-  [`waitForCSSLoaded()`](https://gitlab.com/gitlab-org/gitlab/-/blob/master/app/assets/javascripts/helpers/startup_css_helper.js#L34)
-  helper function.
-
-  ```javascript
-  import initMyWidget from './my_widget';
-  import { waitForCSSLoaded } from '~/helpers/startup_css_helper';
-
-  waitForCSSLoaded(initMyWidget);
-  ```
-
-  Note that `waitForCSSLoaded()` methods supports receiving the action in different ways:
-
-  - With a callback:
-
-    ```javascript
-      waitForCSSLoaded(action)
-    ```
-
-  - With `then()`:
-
-    ```javascript
-      waitForCSSLoaded().then(action);
-    ```
-
-  - With `await` followed by `action`:
-
-    ```javascript
-      await waitForCSSLoaded;
-      action();
-    ```
-
-  For example, see how we use this in [`app/assets/javascripts/pages/projects/graphs/charts/index.js`](https://gitlab.com/gitlab-org/gitlab/-/commit/5e90885d6afd4497002df55bf015b338efcfc3c5#02e81de37f5b1716a3ef3222fa7f7edf22c40969_9_8):
-
-  ```javascript
-  waitForCSSLoaded(() => {
-    const languagesContainer = document.getElementById('js-languages-chart');
-    //...
-  });
-  ```
-
 - **Supporting Module Placement:**
   - If a class or a module is _specific to a particular route_, try to locate
     it close to the entry point in which it is used. For instance, if