Performance (for any system) is really going to be dependent on your particular hardware, your database schema, and the sorts of queries you'll likely be runnin

Performance (for any system) is really going to be dependent on your particular hardware, your database schema, and the sorts of queries you'll likely be running. Somebody else's benchmarks numbers may not mean very much for your own real-world use case. So in short - you should be running your own tests/benchmarks. Nonetheless, ServerDensity has some of their numbers here: https://blog.serverdensity.com/mongodb-benchmarks/ https://blog.serverdensity.com/mongodb-benchmarks/ Also, MongoDB (the company) dogfoods MongoDB (the product) to run their online monitoring/backup service, MMS (http://mms.mongodb.com/ http://mms.mongodb.com/). The scale on that thing (in terms of writes/updates) is huge. There are also several other well-known very-large installations of MongoDB: * Trello * FourSquare * Craigslist * Server Density * Trello * Bit.ly * Chartbeat Most of these DB products are reasonably mature (for a given value of mature) by now - so any of them could probably scale to your workload. So you also need to look at other features as well - developer ease-of-use, ecosystem/tooling, support etc. Put it this way - needing to scale is usually a good problem you want to be having =) - and as the above shows, MongoDB is more than capable of doing it. If you have specific questions - the MongoDB Google Group is a fantastically friendly place to ask: https://groups.google.com/forum/#!forum/mongodb-user https://groups.google.com/forum/#!forum/mongodb-user and the answers they give are pretty detailed.