In the morning we started a deployment of a system that processes our uploads. The system caused an increased load on S3, our storage system. This load caused some uploads to be refused in-flight and the processing of the uploads was delayed by about 30 minutes.
Once we knew what the issue was, we rolled the system back and we contacted AWS about the issues we were experiencing. They are putting the necessary fixes into place so that the deploy will not cause comparable issues in the future.