Yep.

I had to write code to mount an iso image to a server, set the server to boot from it once and reboot the server to start the install.

I had to do it for 4 vendors. Dell, Lenovo, Fujitsu and Supermicro.

4 different vendors, 4 different Redfish APIs.

And what's annoying is that Redfish always looks similar so it fools you into thinking all the vendors do things the same way but no, suddenly some endpoint just doesn't exist in this vendors implementation and you have to scour the docs for this vendors unique magic uri.