Flutter Revitalized Our Codebase and Transformed Our Engineering Team
Article Summary
Sam Moore from Betterment shares how his team rewrote 85% of their mobile app in just over a year without disrupting users. The secret? A methodical approach to adopting Flutter that prioritized team buy-in over speed.
Betterment faced a common scaling problem: two native codebases slowing down feature delivery. Instead of hiring more developers, they made the bold call to replatform their entire mobile app using Flutter. This is their playbook for making it work.
Key Takeaways
- Entire team shipped Flutter code in under 2 weeks after training
- 85% of app migrated to Flutter within one year using add-to-app
- Flutter scored equal or better than native on all evaluation criteria
- Pilot team validated Flutter integration before full team commitment
- Formal training during work hours eliminated individual learning burden
Betterment successfully replatformed 85% of their mobile app to Flutter in one year while maintaining user experience and transforming team productivity.
About This Article
Betterment had separate native iOS and Android teams working on the same app. This created inefficiency and held the company back from being truly mobile-first by late 2019.
Sam Moore's team ran an objective assessment that compared Flutter against native development. They looked at nine criteria including customer experience, CI/CD integration, and developer happiness before deciding to move forward with the replatform.
Betterment used Flutter's add-to-app feature to migrate gradually. This let them avoid rebuilding from scratch while consolidating to a single codebase, and they did it without disrupting users.