Build a Personal Library API with Node.js, Express and MongoDB
By Amanda Ene Adoyi. Updated Wed Sep 24 2025The principle that guides the Mastering Backend community is simple: You can only ever really make progress by building real-world applications which help to solve real-world problems. If you’re looking to build an impressive portfolio, it is crucial that you do not underestimate any APIs that are well-built. A mistake a lot of new backend devs make when building portfolio projects is pressure themselves into building spectacular projects that either become too complicated to finish alone, or don’t address real-world pain points. I would advise that you repeat a mantra and sing it to yourself as you begin this project – Keep it Simple, Stupid. Simple is best, because it allows you address several issues actual users may face and gives your logic sufficient room for expansion without overcomplicating things.
That said, while the project you’ll build here may not address every problem a user would face, it introduces key practices such as documentation and authentication that would help improve your craft in backend development. You’ll be taken on a step by step guide on how to build a personal library API using Node.js, Express and MongoDB.
These are some important concepts and tools you should be familiar with to build this project:

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