[slaymaker1907]

Yeah, I can attest that even banks are really using best effort eventual consistency. However, I think it is very difficult to reason about with systems that try to use eventual consistency as an abstraction. It's a lot easier to think about explicitly when you have one data source/event that propagates outwards through systems with stronger individual guarantees than eventual consistency.

[lmm]

IMO having event streams as first class is the best way to think about things. Then you don't need particularly strong guarantees downstream - think something like Kafka where the only guarantee is that events for the same key will always be processed in order, and it turns out that that's enough to build a system with clear, reliable behaviour that you can reason about quite easily.