Flutter has helped Nubank scale its app at a hyper-growth fintech company by providing an excellent developer experience, long-term viability, and consistency across platforms. The team prioritized factors such as developer experience, long-term viability, no platform specialization, incremental abstraction cost, and non-linear abstraction risk before deciding on Flutter. With Flutter's testing capabilities, hot reload features, robust official documentation, and stable API, the team was able to rapidly ship high-quality apps and adopt a culture of continuous innovation. The migration process involved creating tooling and support for app copy and translations, adapting build, testing, and continuous deployment pipelines, and providing widespread training to teams. Despite some challenges, Flutter has significantly reduced the barrier to new engineers contributing to the app, improved efficiency, and enabled the team to launch new products quickly.