Build uploaded successfully but never appears in App Store Connect / TestFlight

The upload succeeded, but the build failed Apple's post-processing validation — and the only notification is an email to the account holder (often buried or filtered to spam). Common causes: missing purpose strings (ITMS-90683), app icon with an alpha channel, missing arm64 slice / unsupported architectures, invalid entitlements, or a dSYM/asset validation error. Less commonly, processing is just slow (15–60 min, occasionally hours on release days).

1. Wait at least an hour — normal processing takes 15–60 minutes.
2. Check the email inbox of the App Store Connect account holder (and spam) for an "ITMS-…" message; it states the precise problem.
3. Check App Store Connect → TestFlight → iOS builds for a build marked with a red status rather than missing entirely.
4. Fix the named issue (purpose string, icon transparency, etc.), increment the build number, and upload again.
5. If there's truly no email and no build after several hours, check Apple System Status and re-upload.