From the FinishLine AI Blog

How to Fix Code That Lovable Built

Lovable lets you go from idea to app in hours. But the code it generates has patterns that will cause real problems once you try to ship. This guide covers what to look for and how to fix it.

Lovable is powerful. The code it writes is not production-ready.

If you built your app with Lovable, you probably experienced something close to magic. You described what you wanted, and within minutes you had a working app with a real UI, routing, and basic functionality. For prototyping and validation, it is one of the best tools available.

But Lovable optimizes for speed and visual output, not for the things that matter in production: security, performance, maintainability, and reliability. The code it generates is functional but fragile. And the longer you build on top of it without fixing the foundation, the harder it gets to ship.

We have reviewed dozens of Lovable-built apps. The problems are remarkably consistent. Here is what to look for and what to do about each one.

1. Supabase configuration is usually wrong

Lovable uses Supabase as its default backend, which is a solid choice. The problem is how it configures it. In most Lovable projects we review, Row Level Security (RLS) is either disabled entirely or the policies are too permissive. This means any authenticated user can potentially read or modify any other user's data.

What to fix:Audit every table in your Supabase project. Enable RLS on all tables. Write policies that restrict access based on the authenticated user's ID. Test by logging in as different users and verifying that each user can only access their own data.

2. Auth is connected but not secured

Lovable will set up Supabase Auth and create login and signup forms. The basic flow works. But it typically skips important pieces: email verification is not enforced, password reset flows are incomplete, and there is no protection against brute force attempts. Session tokens are often stored in localStorage, which is vulnerable to XSS attacks.

What to fix:Switch to Supabase's built-in session handling with httpOnly cookies. Enforce email verification before granting access. Implement rate limiting on auth endpoints. Add proper error messages for failed login attempts without revealing whether the email exists.

3. Components are massive and duplicated

Lovable generates one component at a time based on your prompts. Each component tends to be self-contained, which sounds good until you realize that means the same logic is duplicated across 10 different files. Form validation, API calls, state management, and styling are all repeated instead of shared.

We regularly see Lovable projects with 500-line components that do data fetching, state management, and UI rendering all in one file. This makes the app hard to debug and risky to change because touching one component does not update the duplicated logic in others.

What to fix: Extract shared logic into custom hooks. Create a shared API layer instead of making fetch calls inside components. Break large components into smaller, focused ones. This is not a rewrite. It is reorganization.

4. No error handling anywhere

Lovable-generated code assumes everything works. API calls have no try/catch blocks. Database queries have no error handling. When something fails, the user sees a white screen or a cryptic error instead of a helpful message. Worse, you have no way of knowing something broke until a user tells you.

What to fix: Add error boundaries around major sections of the UI. Wrap all API calls in try/catch blocks with meaningful fallback states. Set up a basic error monitoring tool like Sentry so you know when something breaks in production.

5. Environment variables are hardcoded or exposed

We have seen Lovable projects with Supabase keys, API secrets, and third-party credentials hardcoded directly in the source code. Sometimes they are committed to the git repository. This is a security risk and makes it impossible to have separate development and production environments.

What to fix: Move all secrets to environment variables. Use.env.local for development and configure them properly in your hosting provider. Make sure your.gitignore excludes environment files.

6. No database migrations

Lovable creates database tables through the Supabase dashboard, but there is no migration system tracking those changes. This means you cannot reliably recreate the database schema, you cannot roll back changes, and deploying schema updates to production is a manual and risky process.

What to fix: Export your current schema and set up a migration system. If you are using Supabase, use their CLI migration tools. Every schema change should be a tracked migration file that can be applied and rolled back.

7. Deployment is not set up for real use

Lovable can deploy to Vercel or Netlify, but the configuration is minimal. There is no staging environment. There is no CI/CD pipeline. There is no automated testing. Every change goes straight to production, and if it breaks something, you find out from your users.

What to fix: Set up a staging environment that mirrors production. Configure a basic CI pipeline that runs type checking and linting before deploys. Consider adding a preview deployment for each pull request so you can test changes before they go live.

The good news: you do not need to start over

Everything described above is fixable without throwing away what Lovable built. The UI is usually solid. The product logic is usually correct. What needs work is the infrastructure: security, error handling, deployment, and code organization.

At FinishLine AI, we specialize in exactly this. We take Lovable-built apps, identify the specific issues blocking launch, and fix them. Most founders start with a Quick Audit to get a clear picture of what needs to happen before investing in fixes.

Ready to get your app launch-ready?

Book a free intro call. We will look at where you are stuck, tell you what needs to happen, and give you an honest assessment of what it will take.

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Written by Matthew at FinishLine AI

FinishLine AI helps founders turn AI-built prototypes into launch-ready products.