I think it's interesting you can distribute more of your "persistent" state to in-memory storage and then distribute snapshots throughout the day. Online game servers often rely on state being in memory rather than being queried on demand. Achieving high performance otherwise is difficult.

However, I wouldn't call this "no-DB." Rather, it's "less-db." Ultimately, historical and statistical data needs to be stored and databases are great for that (and for a stats team).