When the client asks why you billed them for something that was supposedlly your fault and takes a defense when you turn around with the emails and documentation to support that the code is working like it should and was requested by them... Awkward silence... And they still come back with well could you knock off half the hours. Client==fired

Side note.......have been having issues with this clent for a year so it was their time coming.

Shitty-Clent-side: Onclick of submit button, send request to server
Server: Responds with a 500 error.
Shitty-Client-Side: change "Submit" to "Submitted" and backgroumd color to green(because UX is important and error handling can go to hell)

I was thinking of making a devrant client app using flutter & open source it later.