I'll be honest: I didn't build this library because I love ISO 20022. I built it because I had to work with it and I didn't find much in elixir to help with that. ISO 20022 is the global messaging standard for financial transactions - used by SWIFT, SEPA, the UK's CHAPS system, and increasingly everywhere that money moves between banks. It is also, and I say this with the confidence of someone who has spent way too long staring at it, an XML format that feels like it was designed by a committee. Slowly. Over twenty years. With no one in the room who had ever actually written a parser. This is the story of how I went from "I just need to parse one bank statement" to building ex_iso20022 , an open-source Elixir library for parsing and generating ISO 20022 messages. Against my better judgement. It Started With a Real Problem I was working on a transaction processing system and needed to ingest camt.053 files - the ISO 20022 message type for end-of-day bank statements.…