[debergalis]

[meteor dev] Meteor + Mongo may be a good choice for you. The leaderboard example at http://www.meteor.com/examples/leaderboard already has a lot of what you need. The trick is figuring out how to identify each client: whether you have users log in or just assign a unique ID to each client.

[bmelton]

Seconding Matt's suggestion of Meteor. I haven't played with it very much since it first came out, but even at its very earliest versions (from which it has progressed amazingly) I would have suggested it as a perfect fit.

It doesn't "bypass the database" like the GP asked for, but then neither does Firebase really, as it just moves it to the cloud.