Turning a vibe-coded prototype into an app with logins and a backend

To turn a vibe-coded prototype into an app with logins and a backend, you put your own API between the app and a proper database. The API handles sign-in and permissions, holds the keys and secrets, and stores everyone’s data in one place. I usually rebuild the app in that shape, using the prototype as the specification.

The sign you need it: a prototype that keeps its data in the browser looks finished, until a second person opens it on their phone and sees none of the first person’s data.

Why the browser can’t be the backend

• Data saved in the browser stays on that one device.
• If everyone’s data is saved as one record, two people saving at the same moment overwrite each other.
• Anything enforced only in the browser can be changed by the person using it.
• Some things must happen when nobody has the page open: reminders, emails, texts and nightly jobs.

The shape I build

The browser, or the phone app, talks to your API. The API checks who the user is and what they’re allowed to do, then reads or writes the database. Database keys and other secrets stay on the server.

That includes:

• Logins: sign up, sign in, password reset and sessions.
• An admin screen to manage users.
• A database with backups.
• Server-side rules for permissions and anything involving money.
• Emails sent from your own domain.
• Error reporting and analytics.
• Automatic deploys, with a test environment.

What the prototype is worth

I usually rebuild the app rather than patch the prototype. The new version is broken into clear, separate parts, often in React, so it can grow without each change breaking something else.

The prototype is still worth a lot. It’s an exact specification: every screen, every flow and every rule you settled on while building it. Working out exactly what an app should do and look like is usually about a third of the effort, and the prototype has already done that part.

Website, web app or phone app

One backend can serve a website, a web app, and iPhone and Android apps. I build them that way: one codebase for iPhone, Android and the web, on one backend.

Not starting from scratch

When I host and run your app, it starts on the same base as my own apps, with logins and the other common parts already working.

FAQ

Will it work on phones too? Yes. One backend can serve the website, a web app, and iPhone and Android apps.

Do I need to know how to code? No. You describe what the app should do, and the prototype shows it.