Micro Frontend Architecture in Mobile Apps

Micro Frontend architecture is usually associated with web apps — React components loaded from separate bundles, teams owning independent deployment pipelines. But at DBS Bank, we applied the same principles to our iOS banking app, and it worked beautifully.

The problem at DBS

DigiBank served customers in China and Taiwan. Different regulatory requirements, different UI flows, different backend APIs — but a shared codebase. Teams were constantly stepping on each other.

Mobile MFE: the key ideas

• . Feature isolation: each feature (login, transfers, statements) is a separate Swift Package
• . Loose coupling: features communicate through a shared event bus, never directly
• . Independent teams: each squad owns a feature end-to-end
• . Shared kernel: a thin shared layer for navigation, theming, and auth

What we gained

• Parallel development across 3 teams without conflicts
• Feature flags for China vs Taiwan regulatory differences
• Dramatically faster onboarding for new engineers

The hard part

Session sharing across features was the trickiest piece. When a user needs to jump from transfers into statements without re-authenticating, you need a careful contract between features. We solved it with a session token passed through a coordinator — but getting the API right took several iterations.