What is didact?

Didact is a hands-on learning project that walks you through building a simplified version of React from scratch. Instead of just using the React library as a black box, it pairs a series of blog posts with the actual code commits so you can understand exactly what React is doing under the hood. The project is structured as a step-by-step journey. Each section tackles a core concept: rendering elements on the screen, creating the building blocks of a user interface, setting up a "virtual DOM" (a lightweight copy of your app's structure that helps decide what changed between updates), and managing component state. The final post brings everything together into one self-contained guide, covering even the advanced reconciliation engine that modern React uses. This is primarily for developers who want to deeply understand the tools they use every day. A beginner who has built a few apps with React and is curious about how it actually works would get the most out of it. It's a popular resource for coding interviews, since the concepts you learn here, like how the virtual DOM efficiently updates only what changed, are frequent topics. It's also great for anyone who learns best by building rather than just reading documentation. The entire project is a teaching tool rather than something you would deploy in a production app. It skips the heavy performance optimizations and edge-case handling that the real React includes, focusing entirely on clarity and education. You can follow along using the provided interactive code samples in the browser, which means you don't need much setup to start experimenting with the code as you read.