Why Your AI-Generated App Keeps Crashing (And How to Fix It)

Your AI-built app worked perfectly during development. You showed it to friends, they were impressed, everything looked great. Then real users arrived and things started breaking.

This happens to almost every app built with vibe coding. Here's why, and how to fix each issue.

1. No error boundaries

When a React component throws an error, the entire app crashes to a white screen. AI tools rarely add error boundaries because they build for the case where everything works.

The fix: Add error boundaries around major sections of your app. In Next.js, create error.tsx files in your route directories. In plain React, use ErrorBoundary components from a library like react-error-boundary.

The goal isn't to prevent errors — it's to contain them. One broken component shouldn't take down the whole page.

2. Unhandled API failures

AI-generated code typically calls APIs like this:

const data = await fetch('/api/data');
const json = await data.json();
// Use json immediately, no error check

When the API returns a 500, or the network drops, or the response isn't JSON, the app crashes. This is the single most common cause of production failures in vibe-coded apps.

The fix: Wrap every API call in proper error handling. Check the response status. Catch network errors. Show the user a meaningful message instead of a blank screen. Consider a utility function that handles these checks once rather than duplicating them across every component.

3. Missing loading states

AI tools generate components that render data immediately, assuming the data is already available. When a user navigates to a page and the data is still loading, they see undefined values, broken layouts, or crashes.

The fix: Add loading states to every component that fetches data. Show skeletons or spinners while data loads. Handle the three states explicitly: loading, error, and success.

4. Memory leaks from subscriptions

If your app uses real-time features (WebSockets, Supabase real-time subscriptions, event listeners), AI-generated code often sets them up but doesn't clean them up when the component unmounts.

Over time, these leaked subscriptions accumulate. The browser tab uses more and more memory. Eventually the app slows down and crashes.

The fix: Every useEffect that creates a subscription must return a cleanup function that unsubscribes. This is a fundamental React pattern that AI tools frequently miss.

5. Race conditions

When multiple API calls happen simultaneously, AI-generated code assumes they'll resolve in order. They won't. A slower request can overwrite the results of a faster one, leaving the UI in an inconsistent state.

The fix: Use abort controllers to cancel outdated requests. Or use a data fetching library like React Query / TanStack Query that handles this automatically. Race conditions are one of the items on our production readiness checklist — worth reviewing before launch.

6. Session expiry

AI tools set up authentication but rarely handle what happens when a session expires while the user is actively using the app. The user clicks a button, the API returns a 401, and the app either crashes or silently fails.

The fix: Add a global response interceptor that catches 401 errors and redirects to the login page. Show the user a message explaining their session expired. Preserve their location so they can return after re-authenticating. Session handling is one of the 15 items on our vibe coding security checklist.

7. Database query timeouts

Queries that work instantly with 50 rows of test data take 30 seconds with 50,000 rows of real data. The request times out, the app shows an error (or worse, hangs forever).

The fix: Add indexes to frequently queried columns. Implement pagination instead of loading entire tables. Set reasonable timeouts on database queries. Use EXPLAIN ANALYZE to identify slow queries before users do.

The pattern

Notice the common thread: AI tools build for the scenario where everything goes right. Real production software needs to handle the scenarios where things go wrong — network failures, expired tokens, slow queries, concurrent users, unexpected input.

This gap is predictable and fixable. Most of these issues follow the same patterns across every vibe-coded app, which means the solutions are well-understood.

What to do next

If your app is crashing in production (or you want to prevent that before launch), start with the list above. Tackle error boundaries and API error handling first — those two changes alone will eliminate the majority of user-visible crashes.

If you'd rather have a team handle this, request a free audit and we'll identify every stability issue in your app within 48 hours.