So, I have become curious about ISO 20022 and how it relates to ISO 8583.
First, it seems ISO 20022 adoption and implementations were being delayed even before the pandemic hit. I found only a few projects in the SEPA area and in the UK, as well as in the US & Canada.
It seems to me that 20022 is over and above, but also including, card originated financial transactions, so the only way 20022 & 8583 would coexist is if in an Acquirer <=> Issuer <=> Bank card tx chain would have to keep an existing ISO 8583 between Issuer & Bank in place. Am I seeing this right? Nobody out there seems to be talking about how and why you would have implementation of both standards in place.
As well, many, if not all, FI's are providing modern REST API's for integration of ISO 20022 messaging. The XSL based message design is for the purposes of standards definition, the implementation of the data containers and their validation can be, and being, done any which way current technology permits.