Or much lower stakes but the terrible UI that caused Citibank to accidentally give away $500M[1] (though they got it back on appeal [2]). I am always amazed to see the awful, awful software people put up with to do their jobs.

[1] https://arstechnica.com/tech-policy/2021/02/citibank-just-go...

[2] https://www.reuters.com/markets/us/citigroup-wins-appeal-ove...