Given the title I expected a completely different article. The reason being that the opinion that "MongoDB is running out of time" can be supported by a few very strong arguments. There are a few very serious problems with the current technology that give NoSQL alternatives a chance to catch up and grab momentum. For example, MongoDB still has a questionable mmap based storage engine, there are cluster state consistency issues, the cluster topology management is outdated and so on. This article should have been titled "Why I personally like relational databases better than MongoDB". That discussion is incredibly subjective. Source : Very early adopter of MongoDB and use it professionally.