Keep getting '504 Gateway Time-out' errors when using fastlane tools to deploy an app to testflight from the UK. Is iTuneConnect working? I sometimes get a different error which says "Apple Developer website is undergoing maintenannce".. but it isn't.
Dev System Status shows green, naturally.
Others are having different issues connecting w/the backend lately, so it may be yet another outage.
I'm seeing this error randomly but not often (like 1 in 100 app uploads), so far it has always worked on the second try. I think it is an issue on the Apple side as the Gateway error indicates.