German tax department designed an API around polling tax data primarily for companies. I have to find an english link to the full story, but basically:
- company develops api to pull data like a few hundret requests per hour initially, but API returns a 404 after an hour of testing
- later that evening API returns an error stirng saying "open from 9 to 12 and 13 to 14:30"
- next day tax department calls company saying that they cannot handle those requests as the API was designed to be used once a year and that they crashed the server on and on with the sheer amount of requests