[mrkeen]

> Why do so many engineers end up having such a struggle with an event sourcing system, yet the system itself remains highly popular I don’t know.

It's the mental model that's simple: some services write down what happened, other services 'do their own thing' with that information.

I can write the core of the system in 2022, with events like 'Joe wants to buy a bike', 'Joe owes us $200', 'Joe paid us $200', 'Send Joe the bike', etc.

In 2023 I want to build the book-keeping service, in 2024 I want to build the inventory management system, and in 2025 I want to hook it up to a CRM and see if we can try to sell some bike parts to Joe.

Why couldn't I just use REST for that? Because the recipients of the rest calls didn't exist yet.

The bad part of Kafka (in my opinion) is how opinionated the consumer logic is (oftentimes by necessity, because of the whole distributed system thing). Sometimes I just wanna ask "what offset are you up to?", but end up in API hell, and am unable to do it.