Senior Engineer Needed to Fix Stripe / Account State Issue in Existing SaaS

We have an existing SaaS application where a user’s subscription/account state is not always updating correctly after Stripe checkout. The payment itself completes successfully, but in certain cases the application continues to show the previous plan or sends the user back into the wrong account state until the session is refreshed or the user signs in again. The application was built with significant Claude-assisted development, so we need a senior engineer who can review the existing implementation carefully rather than simply generate another patch. The work will involve tracing the flow between Stripe, the backend, database records, authentication/session state, and the frontend to identify where the state becomes inconsistent. We need someone who can: * reproduce the issue from the existing codebase * identify the actual root cause * fix the affected logic without unnecessary refactoring * verify the subscription and account state remain consistent after checkout * check that the fix behaves correctly in the deployed environment Strong production debugging experience is important. We are specifically looking for a senior engineer who can understand an unfamiliar codebase quickly and make a targeted, reliable fix. Please briefly mention any similar SaaS debugging work involving Stripe, authentication, or application state when applying.