knockout VS Polymer

The approach is not new, essentially a variation of Knockout, Alpine, and similar "JS-in-HTML" approaches.

SolidJS and Tauri form another potent combination for creating performant, lightweight, and secure experiences. SolidJS is a reactive UI library that is similar to Svelte in the way it compiles away reactivity and updates the DOM directly, but it also incorporates a fine-grained reactivity system reminiscent of libraries like Marko, Knockout, and MobX.

People act like Signals are a new discovery. KnockoutJS was using them 13 years ago and other libraries used them before that.

Knockout JS is a Javascript library which uses the MVVM pattern to bind data to certain DOM elements. Within Magento, we usually define a View-Model (which is a .js file) and a Template (which is a .html file), and the data in the template file is bound to the view-model, meaning whenever the data in the view-model changes, the template file changes too.

I still use Knockout[0] for almost an identical experience.

0: https://knockoutjs.com/

One of the first uses of this concept was in knockout, which used the same function with and without arguments for write/read access.

To do this, use a Javascript library called knockout.js

You could use a JavaScript framework called KnockoutJS which uses the MVVM pattern.

Magento is built with PHP. A good understanding of PHP is generally enough to perform different development tasks such as building modules. However, developers often need to work with libraries like Knockout.js and Less when developing themes.

Oh, and I know that Wappalyzer detects that Youtube uses Polymer, but here's the thing if you go to the Polymer docs it clearly says "The Polymer library is in maintenance mode. For new development, we recommend Lit."

Polymer - DEAD Recently

It is an open-source JavaScript library based upon Web Components. It is developed by Google. Polymer helps us to create custom elements for building web applications. It's much easier and faster to create custom elements that work like DOM elements.

At least for the YouTube example, if memory serves, they often use Polymer web components for page templating and layout. When you style components through these, oftentimes the CSS styling ends up inline on the page the components are included in.