5 Mistakes I Avoided While Building a React and TypeScript Application

When building React applications, most problems do not appear on day one. They show up weeks later. Components become harder to understand. State spreads everywhere. Performance slowly declines. I recently built a production ready React and TypeScript application, and instead of focusing only on features, I focused on avoiding common structural mistakes. Here are five mistakes I intentionally avoided and why they matter. 1. Putting API Calls Directly Inside Components It is very common to see something like this inside a component: You mount the component. You call fetch. You set state. It works. Until five components need similar logic. Instead, I created a dedicated API layer. Each endpoint had its own typed function. All requests were centralized. Error handling lived in one place. This gave me three advantages: Cleaner components Stronger type safety Easier refactoring Components became responsible for UI, not networking. That separation is small at first but huge later. 2. Overusi