Single-table DynamoDB design for a real-time game (rooms, rounds, leaderboards)

For the H0 Hackathon I built Kauwa Udd, a real-time multiplayer reaction game on Vercel + Amazon DynamoDB. People hear "DynamoDB" and reach for a table per entity — users table, rooms table, scores table. I put everything in one table. Here's the design, why it works for a live game, and the exact key patterns.

Why single-table?

Fewer round-trips: related items share a partition, so one Query fetches a room and all its players.

One thing to provision + secure: my Vercel OIDC IAM role is scoped to a single table ARN (+ its indexes). Less surface area.

It fits the access patterns — and in DynamoDB you design for access patterns, not entities.