I’m sceptical, because I can’t find any examples of banks using it in production, just lots of blog posts by consultants and companies selling event sourcing solutions.
I did work somewhere that used a Kafka stack in production. It wasn’t a compelling use case and they spent almost an entire year on infra and productionizing it. It left me extremely sceptical about anything “big data streams” related :)
Fair enough. But I've used event sourcing in production in two companies. One project was a large scale distributed object store and the other was network equipment (like switches) and network management. The banking example is a classical one but I can't tell you if it's actually used in production. What I do know is that accounting software follows the ledger approach which has a similar spirit, recording transactions, and my guess would be regardless of technology banks also are transaction/event based as their source of truth (even in a COBOL mainframe batch processing scenario).
