Issue

It’s not just you, TestFlight is down for some users [Update: issue resolved]

testflight down

No, it's not just you! TestFlight is currently down for some users, including yours truly. While Apple took a bit of time to acknowledge the issue, the System Status page has now been updated to reflect the issue.

Update: the issue has now been resolved!

According to Apple, the issue started at 8.35 AM Pacific Time and is currently ongoing.  The company notes that "Users are experiencing a problem with this service. We are investigating and will update the status as more information becomes available."