How Senior Developers Think About Component Architecture
Strong React applications aren't just collections of components. They're systems — with clear data flow, defined boundaries, and architecture that scales without breaking.
5 min read
What Is a Component System?
When I first started building in React, I thought about components the wrong way.
I thought a component was a chunk of UI. A card. A button. A navbar. You build the chunk, drop it where you need it, repeat.
That's not wrong. But it's incomplete.
A senior developer doesn't think in components. They think in systems. A component is a unit inside a system — and the system has rules about how data flows, how state is managed, and how each unit is allowed to communicate with the others.
The Three Questions I Ask Before Writing a Component
Before I create any new component, I ask:
What is this component's single responsibility? If it does more than one thing, it should probably be two components.
Where does its data come from? Props from a parent? A global store? A server fetch? The answer shapes everything about how it's structured.
Who else needs this? If more than one page uses it, it belongs in a shared
components/folder with a documented API.
Colocation and Folder Structure
On every project, I follow a colocation principle: keep code close to where it's used. A component used only on one page lives in that page's folder. A component used across the app lives in components/shared/. No exceptions.
This sounds simple. But enforcing it consistently — especially as a project grows — is the difference between a codebase that stays maintainable and one that becomes a maze.
TypeScript as Architecture Documentation
TypeScript isn't just a safety net. When used well, it's living documentation. Your component's Props interface tells every developer exactly what data the component expects, what's optional, and what happens if something is missing.
I write TypeScript interfaces before I write the component. It forces me to think about the contract before I think about the implementation.
The Compound Effect
None of these practices feel dramatic on day one. But six months into a project, when requirements change and features need to be added, the compound effect of good architecture is enormous.
You extend instead of rewrite. You add instead of untangle. That's what makes a system valuable.
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