MongoDB still has an awful reputation on Hacker News but I really appreciate the take from "Why RethinkDB Failed" [0]: > People wanted RethinkDB to be fast on workloads they actually tried, rather than “real world” workloads we suggested. For example, they’d write quick scripts to measure how long it takes to insert ten thousand documents without ever reading them back. MongoDB mastered these workloads brilliantly, w…
I think MongoDB 3.6 is when it became a "decent" DB. Azure CosmosDB provides protocol level for MongoDB 3.6. This offers developers a neat way of using the power of distributed CosmosDB without sacrificing cloud portability.
Those differences may be fine for some use cases, but definitely compromise portability if you want to run or test the same application with a database deployment on GCP, AWS, or your own infrastructure. The lowest common denominator is based on Cosmos DB's underlying limits and features (not a MongoDB server feature set): https://docs.microsoft.com/en-us/azure/cosmos-db/concepts-li....