What does MongoDB do?
MongoDB is a highly popular unstructured, NoSQL document database for powering your applications.
Last updated: March 12, 2025
(MongoDB paid me to write this post. But I was going to write it anyway.)
The TL;DR
MongoDB is a highly popular document database (i.e. NoSQL ) for powering your applications.
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Every app (give or take a few) is powered by a production database
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These days, you can choose between something structured (SQL) or unstructured (NoSQL)
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Document databases are schemaless – you just throw data in, and worry about it later
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MongoDB provides an ecosystem around its document DB – managed services, an IDE, analytics, and search (among other things)
MongoDB is one of the OGs of what I consider the modern tech ecosystem (IPOd back in 2017), and powers apps at some of the world’s largest enterprises. But they’re not a stodgy shop – their cloud product (Atlas) has been growing like a weed recently, and their website actually (gasp) explains what the product does. So let’s dive in and see what they’re all about.
Terms Mentioned
Companies Mentioned
The core MongoDB product: NoSQL database
Unlike SQL databases which are all about structure and rigor, NoSQL is exactly what you think it is – unstructured. Instead of rigidly defining what your data looks like before storing it, you just kind of throw it in there and worry about it later. Querying it is more difficult, but it’s a lot easier to scale horizontally to multiple servers. Neither is better or worse, it just depends on the kind of app you’re building.
If you are going with NoSQL, MongoDB offers probably the best version of it that you don’t need to set up yourself. The MongoDB product is a fully managed, high scale NoSQL (or document, as they call it) database. And like other managed databases, it comes with built in observability, backups, easy to use client libraries, etc.
A refresher – what’s NoSQL?
Although their marketing has moved away from the NoSQL moniker in recent years, the key to understanding MongoDB – and why they had such a major impact on the ecosystem – is to understand NoSQL.
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