Rap Payne

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TypeScript offers three ways to describe data shapes: types, interfaces, and classes. Types are the most flexible option, working for primitives, unions, and complex data structures. Interfaces are designed specifically for object shapes and support extension and merging. Classes provide both structure and behavior but are more complex. The author recommends starting with types for most use cases due to their simplicity, only switching to interfaces when extension is needed, and reserving classes for when you need to instantiate objects with behavior.

TypeScript: Types vs Interfaces vs Classes – Which Should You Use?

Sound advice.
Types can actually be extended
<pre><code class="language-ts">type User = {
 name: string
 email: string
}

interface Admin extends User {
 role: &#x27;admin&#x27;
}
</code></pre>
But I would not recommend to do
<pre><code class="language-ts">type User = {
 name: string
 email: string
}

type Admin = User &amp; {
 role: &#x27;admin&#x27;
}
</code></pre>
Because it can become very slow in big projects.

I also agree with the post for a single and important reason. Interfaces are meant to describe what kind of behavior to expect from the type implementing it. It was never about declaring shape.
e.g. Observability is achieved when we make one type an observer and another one an observable. A person doesn’t stop being a person after becoming an observable.