Kool Smoothie

Overview

Kool Smoothie is a mobile ordering app for a smoothie and healthy-drinks brand, letting customers browse the menu, customize and order drinks, choose takeaway or dine-in pickup, and earn rewards through a points-and-tiers loyalty program. I led the project as Tech Lead and Software Engineer, owning the architecture and building the entire application end-to-end — from the commerce backend to the React Native app in customers' hands.

My Role

As the Tech Lead and Software Engineer on Kool Smoothie, I owned the full technical vision and delivery. I designed the system architecture, made the core technology decisions, and personally implemented the majority of the codebase across both the backend and the mobile client.

• Defined the overall architecture spanning the Medusa commerce backend and the React Native mobile app.
• Led all major technical decisions — authentication strategy, loyalty modeling, data fetching, and state management.
• Built the entire feature set end-to-end, from API routes and backend plugins to native UI and UX.
• Owned code quality, type safety, and the release-ready polish of the app.

What I Built

Loyalty & Rewards

A complete points-and-tiers loyalty system with on-demand tier re-evaluation, reward redemption, and promo codes generated at redemption time and revealed to the customer in-app.

Authentication

Multi-provider authentication supporting phone (OTP), Apple, and Google sign-in, with cross-provider identity linking so a returning customer is recognized regardless of how they choose to log in.

Ordering & Cart

A full cart and checkout flow with tax-inclusive pricing and discount handling, pickup options prioritizing takeaway and dine-in, plus an engaging empty-cart state and add-to-cart confirmation feedback to keep customers moving through the order.

Account & Locations

Account management including a 30-day grace-period account deletion flow, and location-aware store hours that distinguish in-store and delivery availability per outlet.

Payments, Delivery & Store Systems Integration

Engineered custom Medusa commerce plugins across payment gateways (CMI, Stripe), third-party delivery providers, warehouse management system (WMS) synchronization, the Kenzup loyalty and cashback engine, and in-store POS/caisse systems — unifying online ordering with existing retail and back-office operations.

POS Mobile App for Store Staff

Designed and built a companion point-of-sale mobile app that lets store staff scan product barcodes directly from their phones to update inventory levels and pricing in real time, with each staff member automatically scoped to their assigned shop/location for accurate, store-specific stock control.

Marketing & CRM Integrations

Integrated OneSignal and Brevo as campaign providers, giving the marketing team self-serve tools to launch push notification, email, and SMS campaigns across multiple customer segments without engineering involvement.

Localization

Implemented full multi-language support throughout the app, delivering a localized ordering experience for a diverse, multilingual customer base.

App Store Launch & ASO

Owned App Store Optimization (ASO) and managed the end-to-end submission process for both the Apple App Store and Google Play Store, ensuring compliance and store-readiness for public release.

Tech Stack & Architecture

• React Native with NativeWind for the mobile client.
• Medusa 2.x as the commerce backend, extended with custom modules and authentication plugins.
• react-query-kit for typed, cache-aware data fetching and mutations.
• Custom loyalty, phone-verification, and identity-linking logic built on top of Medusa's primitives.

Impact

Delivered as the sole technical lead, Kool Smoothie went from architecture to a polished, feature-complete ordering app — proving that a well-structured Medusa backend paired with a React Native client can support a rich, loyalty-driven commerce experience architected and built by one engineer.