Café Jaf'n

Cafe Jaf’n Kampala is the customer-facing mobile app for the Kampala cafe: browse the menu, save favourites, build a cart, get a delivery fee quote, and place cash-on-delivery orders with address validation so people only check out when delivery is actually possible.

My role

I built the Expo / React Native client end to end—navigation, state, and the data layer that powers menu browsing, auth, checkout, and order history. The app integrates with a backend the team runs separately (orders, quotes, menu data); my focus was making the checkout and location flow feel reliable: maps and Google Places, current location, clear messaging when someone is outside the delivery radius, and a disabled “place order” path until the quote and radius checks pass.

What we shipped

• Authenticated REST flows with persisted sessions and cart state across launches.
• Checkout that combines device location, address search, delivery quotes, and order submission in one guided flow.
• Orders list and detail so customers can track what they ordered after the fact.
• Expo configuration for builds and over-the-air updates so the team can ship fixes without waiting on store review for every change.

Stack

TypeScript, React Native, Expo, Expo Router, Redux Toolkit and RTK Query, NativeWind, Google Sign-In and Apple auth, maps and Places, Firebase where the product needs it, and EAS for distribution.

What made it hard

Commerce on mobile is as much trust and guardrails as UI. Getting bottom sheets, lists, and gestures to play nicely while still enforcing out-of-radius rules and failed-quote handling took iteration—the goal was always that a mistaken tap never becomes a bad order.