Have a client with many thousands of csv, json, xml files detailing insurance prices. Fundimentally they all contained the same data but wildly different format

Have a client with many thousands of csv, json, xml files detailing insurance prices. Fundimentally they all contained the same data but wildly different formats because they were produced by different companies and teams. I used ChatGPT to deduce their format so I could normalize them. Easily underbid their current contractor who was using humans for the work and now I have an easy quarterly billing. :) TBC, I probably could have optimized tokens but contract was profitable and time critical.