Like many companies with complex, high traffic websites, they must have not conducted adequate user observation tests or functionality checks. Although server overload is the primary problem, various aspects of the site are broken.
Web developers should watch and learn from this unfortunate situation.
Here are the things the developers should have taken into consideration to facilitate user success.
(1) load testing
(3) keep the client code, server code, error messages and instructions in sync
(4) user experience should be tested for usability, velocity, validity, simplicity, navigational path clarity, understandability, and error recovery.
READ ARTICLE AT O'REILLY PROGRAMMING: