Introduction
So you have your app running on the iOS Simulator. What to do next to test, preview, and go live on the Apple App Store?
Even though React Native makes mobile development feels like writing JavaScript, the deployment process is nothing like web deployment (one click publishing)! Below is a mental model I found helpful when I published my PlanetFam Quiz app last year.
App Store, EAS, TestFlight, different Builds - an supermarket analogy
The parties involved
- We (the developers): The brand owners
- Our app: The product
- EAS (Expo Application Service): The manufacturer + logistics company
- Apple App Store: The supermarket
- TestFlight: supermarket's tasting room. The product (our app) must be "registered" first before it can be entered in this room
The different app builds
To run a React Native app on a physical iPhone without a Metro server, you must package the JavaScript code into an offline bundle by switching your build configuration.
| Build type | Mental model | Runs on | Who is it for? | Typical command |
|---|---|---|---|---|
| Expo Go | 🧪 Prototyping in the lab | Simulator + physical phone | Fast experimentation & learning | npx expo start |
| Development build | 🍳 Internal test kitchen | Simulator + physical phone | Real-device testing during development | eas build --profile development |
| Preview build | 🧾 Samples / staff or VIP - only stock | Physical phone (via TestFlight) | QA, stakeholders, real-world testing | eas build --profile preview |
| Production build | 🏪 Retail-ready packaged goods | App Store / TestFlight | Public users | eas build --profile production |
Technical requirements
| Build type | Expo Go required? | Phone registered with Apple (UUID)? | Local Metro server needed? | Source code in GitHub? |
|---|---|---|---|---|
| Expo Go | ✅ Yes | ❌ No | ✅ Yes | ❌ No |
| Development build | ❌ No | ✅ Yes | ✅ Yes | ❌ No |
| Preview build | ❌ No | No if via TestFlight, Yes if via Ad Hoc Build* | ❌ No | ✅ Yes |
| Production build | ❌ No | ❌ No | ❌ No | ✅ Yes |
- Ad Hoc = installing a file directly; TestFlight = installing via Apple’s testing app."
Common confusions
Why a Production Build (+ submit) is needed before a Preview Build
The production build/submit step is not shipping your app to users yet. We are doing one specific thing:
Registering your product with the supermarket
That registration creates:
- An App Store record
- Distribution certificates
- Provisioning profiles
- Permission for Apple to host any builds of this app
Without that step:
- TestFlight doesn’t know your app exists
- Preview builds have nowhere to land
- Apple has no legal or technical context for your binary
Why are there two QR codes when I build a development/preview version ?
When we run
eas build --profile development
We get this QR code which is the address of our build
Scan the above QR code to install the app (the app icon will show up).
Then when we run the Metro server
npx expo start
The second (smaller) QR code appears. This is the Metro server address.
Scan this smaller QR code to hot reload the code changes.
- QR 1 (The Shell): This is the "house" for your app.
- QR 2 (The Furniture): This is the actual code/logic moving into the house.
Next
I plan to write a 3 part series explaining a bit more details on each of the development phases: development, preview, published, and maintenance. Hopefully, they clear up some of the most confusing parts of iOS app development!
Questions
Please comment below and I will try to explain as much as possible..
Top comments (4)
This supermarket analogy is 🔥 — especially the way you explained TestFlight as the tasting room.
I’ve seen so many people (myself included) get confused between development vs preview vs production builds, and this makes the mental model click instantly. The two-QR explanation is another great touch — that’s one of those things you only really understand after struggling with it on a real device.
Thanks for your reply!
Yes I realise that these are some of the most confusing steps and I have been caught up quite a few times. So, writing this article really clears up many knowledge gap I had. I’m glad it helped!
That's good 👍🏻
Thanks! Hope it helps!