Coinbase Harry Tormey May 14, 2021

Announcing Coinbase’s successful transition to React Native

Article Summary

Coinbase migrated 56 million users from native iOS/Android to React Native without breaking their $1.8B quarterly revenue stream. Here's how they pulled it off.

Between 2018 and 2021, Coinbase completely replatformed their mobile apps, rewriting 200+ screens and retraining 30+ native engineers. They took a methodical approach: test small, prove value, then scale up stakes.

Key Takeaways

Critical Insight

Coinbase successfully unified their mobile engineering around React Native, dramatically improving developer velocity while maintaining quality for 56 million users.

The article reveals their specific timeline, the brownfield trap they avoided, and why they rewrote Android first instead of iOS.

About This Article

Problem

Coinbase hired mobile engineers at half the rate of web engineers in 2017. Mobile engineer productivity stayed flat while web engineers got noticeably faster at their work.

Solution

Harry Tormey's team took a three-phase approach. They started with a greenfield Pro app, then rewrote the brownfield onboarding layer, and finally rebuilt Android and iOS from scratch. They skipped incremental brownfield updates after seeing how that approach had caused problems at Airbnb.

Impact

The feature team went from 8 engineers down to 5 across both platforms. React Native contributors grew from zero to 113, pulling in web engineers too. Both Android and iOS saw positive results when they rolled out, and the service kept running smoothly for 56 million users.