Problem
I noticed fewer Apple Pay payments while Link, card and Google Pay remained in use. Failures happened before the backend call and did not produce useful client or server errors.
Context and constraints
This was a production checkout flow with limited diagnostic evidence. Payment-method availability did not demonstrate that the actual confirmation flow worked. The investigation needed a concrete reproduction rather than another plausible explanation.
Existing architecture
The browser initiated Apple Pay from a checkout interaction. An asynchronous operation sat after the button click and before the activation-sensitive payment step.
Investigation
Initial Claude/Codex suggestions led to changes that did not solve the problem. I reverted those changes, configured Stripe Apple Pay with HTTPS locally and reproduced the failure in my test setup. With a concrete reproduction, I directed Codex to investigate the browser behavior.
Root cause
In this incident, an asynchronous operation after the click broke the user-gesture requirement needed by the Apple Pay flow. The issue was in the timing of the browser interaction, before the backend was called.
Solution
I removed the asynchronous call from the activation-sensitive path. The change addressed the reproduced cause and kept the fix narrow.
Architecture and implementation
The important boundary was between a direct user interaction and the step that required that activation. The incident is an account of this specific flow; it is not a claim that every asynchronous operation always breaks every wallet integration.
Diagnosis
- Production failure
- AI hypotheses did not resolve it
- Revert and reproduce
- Inspect user activation
Root cause and fix
- Button click
- Async work lost required activation
- Remove async call from that path
- Verify the payment flow
Result
The change resolved the issue in my verification, according to the incident account. No quantified revenue recovery, conversion uplift or final regression artifact is available, so none is claimed.
Tradeoffs
A narrow change reduces the amount of behavior altered during a production incident. Reverting an unsuccessful suggestion is part of the investigation, even when the suggestion sounds confident.
What I would carry forward
Keep a repeatable wallet-flow regression check and record the exact browser, device and interaction sequence. AI can accelerate hypothesis generation and code investigation; responsibility for evidence and verification stays with the engineer.