What are the best hands-on resources for improving programming skills beyond the beginner level?

You may not need another platform at all. Pick a small tool you use regularly—something like grep, ls, or a log viewer—and build your own version. Start with a narrow feature set, then add functionality as you understand the problem better. That gives you realistic design and debugging practice without turning the work into a collection of disconnected exercises.

Reading existing software is another important way to improve. Choose a well-written open-source project you like and spend time tracing how its pieces fit together. A classic Unix source-code commentary can also be useful for learning how experienced programmers approach systems code. Once you understand a project, making a small contribution can provide practical feedback and expose you to real-world development habits.

A project doesn’t have to come from a formal course. Keep a list of small ideas that seem interesting, even if they occur to you at random, and choose one that is just difficult enough to stretch you. Building something you personally care about is often more motivating than completing a predefined sequence of challenges.

Of those options, CodeCrafters sounds closest to what you want. You build working versions of things like Redis, Git, a shell, or an HTTP server in small stages. Each stage has tests to verify your implementation, and there are hints if you get stuck, while still requiring you to write the code yourself. The main drawback is that most of the material is behind a paid plan.

Boot.dev is more of a structured curriculum. It can be useful, but it feels more like taking a course than independently solving a realistic project. Build Your Own X is excellent for finding project ideas and tutorials, though you’ll usually be following instructions and won’t get much feedback when something goes wrong.

Whatever resource you choose, a test suite or code review is valuable. That feedback loop makes it easier to practice deliberately and avoid falling back into having AI write everything.