MongoDB is a fine database IMO. The main issue I have with it, is that they dropped SQL interface and instead invented a less expressive query syntax. Really

MongoDB is a fine database IMO. The main issue I have with it, is that they dropped SQL interface and instead invented a less expressive query syntax. Really there are some great features to MongoDB and it's relatively easy to maintain. I wish it had better tooling for modifying existing document structures such as ALTER TABLE... but the automatic sharding is nice.