Frontend

Best practices for building UI that is correct, accessible, fast, and type-safe. The principles below are framework-neutral — they hold whether you write React, SolidJS, or anything else. The framework-specific how lives in references that you load on demand, because the single biggest source of frontend bugs is applying one framework's mental model to another.

Framework Selection — do this first

The shared principles tell you what to aim for. They do not tell you how to write reactive code, because that diverges sharply by framework and getting it wrong is the most common cause of "my UI won't update" and "this re-renders too much" bugs. So before writing or reviewing reactive logic, detect the framework and load exactly one reference.

Detect in this order; stop at the first signal: