Shopify's Shift from React Native to Swift and Kotlin

Shopify’s Native Break

Shopify, the ecommerce platform, is leaving React Native for native development. It’s a shift driven not by frustration, but by economic advantage. AI tools have changed the cost-benefit analysis of building mobile apps.

Why native development is more attractive to Shopify

Shopify’s pivot to native development marks a turning point in how companies balance cost and performance in mobile app development. AI coding agents have significantly reduced the economic burden of maintaining separate codebases for iOS and Android. This shift allows companies to potentially regain some performance and integration benefits that come with native development.

The Tech Stack: React Native vs. native

React Native promised to eliminate the need to build apps twice for iOS and Android. For years, that savings was crucial for companies like Shopify. Apple’s Swift and Google’s Kotlin might be more performant and offer closer integration with platform tools, but the cost of maintaining two separate codebases often outweighed those benefits. In 2020, building the Shop app in React Native was the clear choice.

AI’s role in the transition

Shopify’s foray back into native development was jump-started by its coding agents. Initially, the tech was meant to bridge the gap between iOS and Android implementations. Now, AI’s capacity to understand existing code and implement equivalent features in the opposite platform has turned the economics on their head. An AI can reference an iOS feature and rapidly build its Android counterpart, or vice versa. While two native codebases still require maintenance, the cost of duplicated implementation work has shrunk. Rather than supporting a single, bloated React Native codebase, Shopify can maintain two leaner, more performant native codebases. In turn, this shift gains them better access to platform-specific APIs, tighter integration with SwiftUI on iOS and Jetpack Compose on Android, and potentially better performance.

The Helix system

The transition to native wasn’t a wholesale rewrite of the app. Shopify’s in-house Helix system broke the migration into small, manageable checkpoints. Each checkpoint required the AI to implement a feature, pass tests, match the original feature visually, survive two adversarial code reviews, and receive human approval. This tight feedback loop ensured the AI’s work met Shopify’s standards of quality. It also meant the AI couldn’t rush ahead and create unmanageable messes of code. The system’s structure kept the AI’s output small and trustworthy.

The impact on app performance

Shopify’s transition to native development paid off in performance improvements. The Android app’s cold startup time dropped by about 50% and its size shrank by 109 megabytes. Session crashes on Android also fell by roughly 10 times.

What this means for developers

Shopify’s experience illustrates how companies can maximize their tech stack as AI developments continue to shape the software landscape. This case study offers a few key insights for developers and businesses alike. AI’s impact isn’t limited to speeding up coding. It can alter which technologies make the most economic sense. Companies facing similar decisions may want to explore how AI coding agents can influence their own trade-offs.