Mastering Brownfield React Native: Multi-Host & Multi-Bundle Strategy

Why Brownfield Architecture?

In large banking apps like BRI, rewriting everything from scratch is often impossible and risky. I utilized a Brownfield approach, embedding React Native into existing Java/Swift native apps to modernize features without losing the core native stability.

The Multi-Host & Multi-Bundle Concept:

To ensure the app stayed lightweight and modular, I implemented:

• Multi-Bundling: Breaking the JavaScript bundle into smaller, feature-specific files. This prevents the "heavy" loading of the entire app when only one feature is needed.
• Multi-Host Instance: Allowing different parts of the native app to host separate React Native instances simultaneously without memory leaks.

This architecture allowed for independent feature updates, meaning the business could push new UI changes without needing a full App Store submission for every minor tweak.