Add some FE examples

doc/development/transient/prevention-patterns.md

@@ -6,5 +6,39 @@ info: To determine the technical writer assigned to the Stage/Group associated w
 
 # Preventing Transient Bugs
 
-This page will cover architectural patterns developers should employ when building new features to prevent transient bugs.
+This page will cover architectural patterns and tips for developers to follow to prevent transient bugs.
 
+## Frontend
+
+### Don't rely on response order 
+
+When working with multiple requests, it's easy to assume the order of the responses will match the order in which they are triggered.
+
+That's not always the case and can cause bugs that only happen if the order is switched.
+
+**Example:**
+
+* diffs_metadata.json (lighter)
+* diffs_batch.json (heavier)
+
+If your feature requires data from both, ensure that the two have finished loading before working on it. 
+
+### Simulate slower connetions when testing manually
+
+Add a network condition template to your browser's dev tools to enable you to toggle between a slow and a fast connection.
+
+**Example:**
+
+* Turtle:
+  * Down: 50kb/s
+  * Up: 20kb/s
+  * Latency: 10000ms
+
+### Collapsed elements
+
+When setting event listeners, if not possible to use event delegation, ensure all relevant event listeners are set for expanded content.
+
+Including when that expanded content is: 
+
+* **Invisible** (`display: none;`). Some javascript requires the element to be visible to work properly (eg.: when taking measurements).
+* **Dynamic content** (AJAX/DOM manipulation).