What are the best ways to learn back-end development?

If you're already fluent in JavaScript, I suggest checking out some courses on platforms like Udacity or Udemy for Node.js. Udemy often has great deals—sometimes under $20. After you grasp the basics, try diving into Express.js or start with other simple frameworks before tackling larger ones. If you're looking at databases, MongoDB is a common choice, as it lets you use JavaScript on both the front and back end.

While I appreciate the input on MongoDB, I recommend learning SQL instead. As a full-stack developer, having a solid grasp of SQL is crucial and may serve you better in the long run than focusing on MongoDB just because it's related to JavaScript.

Absolutely, Node.js is a must. Don't forget to get comfortable with bash and git, too! You might find helpful resources like backend roadmaps on roadmaps.sh very useful. Also, consider learning about Docker and Kubernetes since back-end and DevOps are starting to blend together. And remember, understanding cloud platforms is essential!

A hands-on approach works great! Work on a UI web app or a personal project, and once you've made progress, try flipping your monitor around to see it from a back-end perspective.

.NET is also a growing field. If you’re interested, learning .NET Core and Web API could benefit you, especially if you're comfortable with C#.