Technology
JavaScript
Everything we ship to a screen is JavaScript at the end. We write it carefully, type it when we can, and we do not send a novel to do a button's job.
What it is
JavaScript is the language the browser already speaks. Every button, every client-side form, every React tree becomes JavaScript before it runs. On the server, Node and Deno run the same language. It is not a framework. It is the runtime of the web.
The language is messy, ubiquitous, and still the thing you cannot opt out of if you ship to a screen. TypeScript, React, Vue, and Svelte are opinions on top. JavaScript is what actually executes.
What it does
Teams use it for interactive sites, single-page apps, serverless functions, browser extensions, and desktop shells (Electron). If the product has a front end, JavaScript is in the bundle even when the source is TypeScript.
We write it carefully, type it when we can, and we do not send a novel to do a button's job. Performance is a JavaScript problem as much as a design problem.
Why we use it
The language the browser already speaks.
TypeScript on top for products that last. Progressive enhancement where it matters. Third-party tags load when they are needed. We test the journeys that make money, not a lab profile.
If the offer is not in the HTML, the script is in the way.
Built on it
Netflix
The web app and a large share of TV UI work are JavaScript at runtime.
PayPal
An early Node.js adopter, with JavaScript on the payment web stack.
Meta
Facebook, Instagram on the web, and WhatsApp Web are JavaScript applications.
Gmail, Maps, and Docs are among the largest JavaScript applications ever shipped.
Wikipedia
The site and its editors run a substantial JavaScript layer on every article.
Tell us what needs to ship.
You use a working prototype before the production build goes ahead.