We use MongoDB to build eCommerce apps at my company, using a Ruby-based platform that can be easily extended. Here's a couple of the reasons why we use it: 1.

We use MongoDB to build eCommerce apps at my company, using a Ruby-based platform that can be easily extended. Here's a couple of the reasons why we use it: 1. It's easier to extend the pre-defined model classes that our platform provides with new fields, without having to manage migrations. Mongoid manages the schema for you. 2. Because our apps represent an eCommerce "storefront", they are _not_ the system of record for our clients. Each client has their own way of storing this data, and fulfills orders through an order management system. They control all of that, obviously, because it contains important financial data that they need to retain. 3. MongoDB is a well-supported database, with a large ecosystem and lots of users. It's a familiar DB for new developers that we hire, as well as for systems integrators who are also building apps on our platform. Using MongoCloud and official support from MongoDB, Inc., hard questions about our database technology are just a phone call away. Postgres is amazing, but it isn't supported by a company you can turn to when shit really goes south, so it's a scary choice for enterprise service providers. 4. It doesn't have terrible documentation. Pretty much everything is there, it's just hard to find. I really wish they would use something other than Confluence because the search on there is awful. All this aside, I still use Postgres on my own Rails apps because I don't need the complex features of MongoDB. But after a few years at my current job, I can definitely see why Mongo was chosen.