Start using Charles proxy in your current project and present how it helped you in the project? Provide examples where it brought in values maybe with a bug report where debugging steps are mentioned.

Update the API details 

To Long title

To different API data [ For example: try to update item as out of stock or add swatches]

Simulating the Error use cases by updating the API request and response details

To 404 or 500 API Error

Use throttle networking to test the application at different network speeds

Check the tracking calls triggered with events/props/evars if any on page load or custom link click

Block the API call and check the UI error message shown