Comment by computerfan494

At the end of the day the author and those they are arguing with mostly agree, they simply disagree on what the word "delivery" means. Given the author's background, I wonder if the issue is that they're focused mainly on lower levels of the stack, while those who disagree mainly work with traditional applications that do things like send email, respond to webhooks, update databases, etc.

The reason I think it's important to be pedantic about distinguishing between "delivery" and "processing" is that I have seen plenty of higher level systems that have incorrectly not implemented idempotency and had bugs as a result. I have seen many folks be confused by Kafka's "Exactly-Once Semantics" feature and introduce major bugs into message processing pipelines. The author, who clearly understands these fundamental design challenges, is not my problem. It's everyone else who struggles to design safe, idempotent exactly-once systems.