I created this piece of content for the purpose of entering the H0: Hack the Zero Stack hackathon. #H0Hackathon The problem (that's harder than it sounds) "Don't sell more tickets than you have" sounds trivial until 10,000 people click Buy in the same second. The naive fix — a single remaining counter you decrement on every purchase — falls apart under load. And when you try to go multi-region, it gets worse: with eventual consistency across regions you can oversell during the replication window. I wanted a flash-sale engine that is globally fast AND strongly consistent AND operationally simple — all three. That combination is precisely what Amazon Aurora DSQL is built for, so I built DropZero on it for the hackathon. The trap I almost walked into Aurora DSQL is a serverless, PostgreSQL-compatible, multi-region active-active SQL database.…