In today's frontend world, it's easy to reach for React, Vue, or Svelte the moment a project needs interactivity, state management, or routing. But the modern browser has evolved dramatically. With native DOM APIs, the History API, Web Components, and powerful language features like Proxies, you can build rich, performant single-page applications (SPAs) using nothing but Vanilla JavaScript. This approach gives you: Smaller bundle sizes Better performance (no virtual DOM overhead) Full control and understanding of your code No framework lock-in or version churn Let's explore how to create a lightweight "Vanilla JS Framework" using five key pillars: Vanilla JavaScript The DOM Routing Web Components Reactive Programming with Proxies We'll build toward a simple todo-style SPA that demonstrates all of them working together. 1. Vanilla JavaScript: The Foundation Start with plain, modern ES6+ JavaScript—no transpilers, no build tools required for small-to-medium apps (though you can add Vite later if you want).…