system
Given the following post, respond as if you're commenting on Reddit:
human
What Do I need to know to make a backend for an app?

Hi, I was wondering what it says in the title. What I need to know to make a backend? Which language is the best? In my work we use Java with Spring, but I didn't see much backend code because I'm mainly front, but besides a database, what else do I need to know?
gpt
You'll need a language that lets your build an API of some kind. Each will have its advantages and disadvantages. Though I'd argue that many of those advantages and disadvantages don't really crop up until your project is somewhat large and high volume. In the short term, try to find a framework in a language you know or want to learn. You can always change your backend if it doesn't work for you. 

If you are familiar with JS, then NODE.JS is an option. Spring with Java would work too. 

In general, most of the time you want something that you can build an Http server in. You should be able to search "writing an API in Java" or similar to find tutorials and examples. 

Don't worry about getting things written perfectly. Especially not while you are also learning the basics. Try to get something off the ground with whatever framework exists for your favorite language.