Marketing sent the email. The link opened the app store instead of the promo screen. Support tickets mentioned "the link worked on Android but not iPhone." QA could reproduce it only on a physical device, never in the simulator.
If you are new to Flutter deep linking, that story probably sounds familiar.
What is a deep link? A URL that opens your app and navigates to a specific screen, not just the home screen. Example: https://example.com/promo/123 should open your app directly on the promo details page.
Why beginners struggle: three separate systems must agree before that works:
Your website (verification files that prove you own the domain)
