A shared codebase can make a small team faster, but only when the boundary between product logic and platform behavior stays deliberate.
Share the product surface
Keep domain rules, validation, API contracts and most interface components in the shared web application. That is where reuse produces the largest return.
Isolate platform capabilities
Wrap notifications, secure storage, deep links, permissions and device APIs behind small platform adapters. Web code should not need to know which native plugin implements a capability.
Treat native projects as source code
Capacitor's ios/ and android/ directories contain project configuration, permissions, signing settings and native changes. Version them, review their diffs and validate release builds on both platforms.
Test the real device path
Responsive browser testing is necessary but not sufficient. Verify keyboard behavior, safe areas, back navigation, offline states and permission flows on representative devices before release.