Questions, answered
What is LotZero?
A global live-auction marketplace where bidders worldwide compete in real time, with a guarantee of zero oversells and zero double-spends.
How does it stay correct when two people bid at the same instant?
The money ledger runs on Amazon Aurora DSQL, which uses optimistic concurrency control with strong consistency. Conflicting transactions are detected at commit and retried; exactly one writer wins, with no cross-Region locks and no lost writes.
Which AWS databases does it use?
Aurora DSQL for the money and scarcity plane (wallets, bids, holds, settlement) and Amazon DynamoDB for the social firehose (chat, presence, reactions, leaderboards, activity feed).
Why two databases?
Different jobs. Money must be exactly right under global contention (DSQL, strongly consistent). The firehose is high-volume and append-mostly, where eventual consistency is fine (DynamoDB).
Is this real money?
No. The demo uses sandboxed wallets. Production would add a payment processor, KYC and tax.
How is zero oversells proven?
The Proof page fires hundreds of concurrent claims tagged across five AWS Regions and measures the invariants live.
What auction types are supported?
English ascending, Dutch falling-price (first claim wins), and fixed-price drops.
Can it scale to millions?
Aurora DSQL is serverless and scales horizontally, DynamoDB handles very high write volume, and the front end is edge-rendered on Vercel.