GoSIM — eSIM app rebuilt in React Native

Context

GoSIM sells travel eSIMs inside the Goubba ecosystem: pick a destination, pay, and install a data plan without visiting a shop. The first version was a Vue 3 app wrapped in Capacitor. As the product grew — top-ups, partial payments, guest checkout, loyalty points, marketing campaigns — the WebView shell reached its limits: janky transitions on mid-range Android phones, payment SDKs with partial Capacitor support, and a custom bridge for every native feature.

Role

Main contributor on the mobile rewrite (~90% of commits): app architecture, migration plan and most features. Backend contributions in Laravel for the same features — points, maintenance mode and payment flows — so each one shipped end to end.

Challenge

• Replace a live app without a feature freeze — v2 had to reach parity while v1 kept shipping fixes.
• Native payments — Stripe, PayPal and Airwallex each require their official SDK and confirmation flow.
• Data for marketing — campaigns need attributed installs and purchases, and links that open the right screen.
• Device compatibility — a wrong "yes" means a paid plan the user cannot install.

Approach

Expo Router with thin routes

File-based routing on Expo, with logic in feature folders (auth, destinations, checkout, eSIMs, points). The same structure later made GoSIM a mini-app package of the Go super-app, in a pnpm + Turborepo monorepo.

Three payment providers, one checkout

Stripe, PayPal and Airwallex integrated through their native SDKs behind a single checkout flow; partial payments and top-ups reuse the same path.

GoPoints loyalty system

Points earned on every purchase and redeemed for coupons — app screens (balance, coupon codes, results) and the backend rules that grant and spend points.

Deep links, AppsFlyer and Meta

Custom gosim:// scheme, universal/app links and AppsFlyer OneLink route campaign links to the exact destination or offer; AppsFlyer and the Meta (Facebook) SDK provide install and purchase attribution.

Running a live app

Remote maintenance mode without an app-store release, Firebase push notifications and in-app messaging, and centralised error handling with recoverable states.

Compatibility check before checkout

A native iOS/Android module reads the device's own eSIM signals, published as react-native-esim-compatibility-checker.

Results

• Native-feeling iOS and Android app from one TypeScript codebase.
• Three payment providers, loyalty points and campaign deep links in production.
• Attribution data used by the marketing team to run campaigns.
• Fewer "my eSIM doesn't work" support cases.