React Native at Scale

Manjiri Moge, a staff software engineer at Coinbase, reveals how React Native has become the backbone of one of the world’s most high-velocity mobile apps—not just for speed, but for reliability, scalability, and developer experience. She argues that React Native’s real power lies not in writing once and deploying everywhere, but in creating a unified engineering culture where web and native developers collaborate seamlessly. At Coinbase, performance isn’t measured in abstract benchmarks, but in how quickly users can check their crypto balance—what she calls the 'critical operation.' Her team uses four core metrics: cold start time, navigation feel, error rates, and end-to-end journey duration. What’s more, she warns that performance regression is inevitable without automation—"performance is a flat circle"—and that guardrails like ESLint, TypeScript, and AI-powered code reviews are essential to prevent drift. She also exposes the hidden costs of overfetching, polling, and preloading, and shows how GraphQL with deferred fields and Suspense instrumentation help optimize data loading. With the new React Native architecture, JSI and Turbo Modules promise to eliminate the old bridge bottleneck, making native integrations faster than ever. And in a bold claim, she shares that over 50% of Coinbase’s code is now AI-generated—agents that follow internal conventions to write idiomatic React Native code, reducing friction and accelerating delivery.