Ship it and know your limits
An app on your laptop helps nobody. This lesson puts Ravi's reorder app on the internet for five partner shops, shows you how to watch it, what it costs, how to undo a bad change in minutes, and how to tell when a prototype has done its job and an engineer should take over.
By the end you can
- Explain what deploying means and connect a GitHub repository to a host that builds on every push
- Set environment variables in the host's settings and keep secret keys out of the browser
- Run a pre-launch checklist, including a tested way to roll back
- Read an error report, handle an incident and write a short incident note
- Keep a monthly cost sheet, and decide when to hand over to an engineer and how
The everyday picture
Think of a good home cook who starts selling food from a small stall at the weekly market. At home, mistakes stay in the family. At the stall, strangers eat the food. So the cook tastes every new dish before it goes on the menu board, keeps the old recipe card in case the new one fails, writes down every complaint, and checks each month whether the stall's rent and gas cost more than it earns.
Then one day an office asks for lunch for 500 people every day, with invoices and food-safety papers. A good cook knows that this is a job for a proper kitchen, and hands over the recipes, the notes and the list of what customers liked. Shipping an AI-built app is the same: put it where people can use it, taste each change first, keep a way back, watch it, count the money, and know when the job has grown past you.
Deploying: your app on someone else's computer
To deploy means three things happen. Your code is built, it runs on a computer that someone else owns and keeps switched on, and that computer answers at a public address such as reorder.example.com. The company that runs that computer is your host.
An AI-built web app usually goes live in one of two ways:
- The app builder's own publish button. App builders such as Lovable, Bolt or Replit can put your app online from inside the tool. It is the fastest path. The trade-off is that the tool decides much of the setup, and moving away later can take work. The button's name and what it includes differ by tool.
- GitHub plus a hosting platform. Your code lives in a GitHub repository (GitHub), and you connect that repository to a host such as Vercel, Netlify, Cloudflare Pages or Render. These are examples, not a recommendation. From then on, every push builds and deploys a new version. This is the path the rest of this lesson uses, because it keeps your history and your Git undo button.
Most hosts that build from Git make two kinds of deployment. A preview deployment is made for each branch or pull request and gets its own link, so you can try a change on a real server before any shop sees it. A production deployment is made when you push or merge to your main branch, and it replaces what users see. On Vercel, for example, pushing to any other branch makes a preview, and the first deployment of a new project always goes to production.
Your secrets reach the deployed app through environment variables. In Data and security basics you kept them in a .env file that never goes into Git. On the host you type the same names and values into the project's settings, often with separate values for preview and production. Two rules catch beginners. First, on most hosts a changed variable only takes effect in the next deployment, so redeploy after you change one. Second, frameworks put some variables into the browser on purpose: in Next.js any name that starts with NEXT_PUBLIC_, and in Vite any name that starts with VITE_, is copied into the JavaScript every visitor downloads. The public database key may go there. The secret key never may.
Last, the address. The host gives you a free link such as your-app.example-host.app. For a nicer one you buy a domain from a registrar for roughly $10 to $20 a year, add it in the host's settings, and copy one or two DNS records the host shows you into the registrar's settings. The host then gets a certificate for HTTPS for you, so the padlock appears and nobody on the shop's Wi-Fi can read the traffic. Most current hosts do this automatically and for free.
Quick check
The app is live for five shops. Imran pushes a new branch called order-total with an unfinished change. What do the shops see?
A push to a branch other than main makes a preview deployment at a separate link. The shops keep using production at the usual address until the change is merged into main. That is what lets you test a change on a real server first.