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Background When we write programs, we have a quiet assumption that goes unnoticed until it gets explicitly questioned — when you send a request, it either succeeds or fails; even when you query a database, it either succeeds or fails. It always holds...

The Real Problem: When Side Effects Matter More Than Data While working on the billing pipeline, I had a straightforward goal:Listen to events from Kafka and send billing reports to customers. Simple on paper.Until I started thinking about what coul...
