[lxgr]

The large card networks have so many proprietary behaviors and extensions that I really doubt whether any common standard would even make sense at this point.

And if you look at how "modern" ISO 8583 is evolving, almost all changes and extensions are already happening in TLV-like subfields (where a new field unexpectedly appearing doesn't make existing parsers explode spectacularly), and the top-level structure is essentially irrelevant.

Of course, it's a significant hurdle to newcomers to get familiar with that outer layer, but I don't get the sense that catering to these is a particular focus by either network. ISO 8583 is also a great moat (one of many in the industry, really) for existing processors, which have no buy-in to switch to a new standard and the networks need to at least somewhat keep happy.

[throwway120385]

I thought that chip-in EMV was bad until I saw some of the stuff coming out of Discover cards for contactless EMV. Buying a test card set from somewhere like B2 Systems was very beneficial even just integrating an EMV reader from a hardware device to a payment processor.

[lxgr]

The problem is that the contactless stuff is all custom per network.

Some of the implementations are reasonably close to contact EMV; others might as well be a completely different stack and technology.

[BiteCode_dev]

In this world and age of AI, having this kind of inside knowledge that is scattered, usually behind paywall and nda, and always to be updated, is a real advantage.

Because no LLM will be able to replace you for quite a while.

[happosai]

Job security via obscurity.

[_blk]

You're right but that's because it's already come to this. Would it have been that hard to say: these are the standardized fields usable only in accordance with the standards and these are the custom fields for your own bs.