[madarco]

I can share why I used it for 2 products (and regret not using it in 1): - if you are using an ORM library, it avoids unnecessary sync/migration steps by moving the schema definition only in the ORM (as opposed as in the ORM and synced to prostgres/mysql) - It is the fastest while used in-memory. I run the full suite of integration tests for a medium complexity api in 30 seconds. On one product (w/ postgres) we did run tests on sqlite but it's much slower (10x times). - It includes a lot of small features common in web sites or apis: media storage, queues, auto removal of old rows, full text search, geo queries. A dedicated solution (solr, s3, redis) would be better, but for small scale projects mongo was just fine (and a single thing to maintain, backup, monitor) - easy to learn, never hired someone with previous mongo experience, but it was never a problem: having a less expressive query language means that's easier