At first bluff, I'd expect a ton of example and implementation code to be open-sourced. I still don't know what nightmare code is crawling CSV/ZIP (forget which

At first bluff, I'd expect a ton of example and implementation code to be open-sourced. I still don't know what nightmare code is crawling CSV/ZIP (forget which) files daily doing ACH transfers, but afaik that's still how electronic banking is done? Would love to learn I'm outdated there.