Digital health coaching migrated from legacy to a modern web app
A digital health coaching product inside Johnson & Johnson, moved off its legacy application onto a modern web app — the same service for the people using it, no pause while it happened, and every release through the enterprise compliance process.
The challenge
Shipping a modern front-end inside a highly regulated healthcare enterprise is as much about the environment as the code: legacy code to tame, strict release and compliance processes to respect, and authentication that has to fit the corporate identity systems.
Our approach
We worked on two tracks. On the first, the new front-end took shape: server-side rendered, with scoped component styles and a central state store, written test-first and shipped through CI. On the second, we kept the legacy application alive: testing, debugging and refactoring, so day-to-day users saw no disruption. Between them ran a back-end API proxy covered by unit tests, and enterprise single sign-on fitted to the corporate identity system.
The results
The people using it never saw a gap: the new application arrived fast and consistent across browsers, while the legacy one kept running until it was no longer needed. Every release went through the enterprise compliance and release process.
What we did
- Delivered a new front-end with server-side rendering, scoped component styles, and a centralized state store
- Developed test-first and shipped through a continuous integration pipeline
- Tested, debugged, and refactored the legacy application in parallel
- Built the back-end API proxy, covered by unit tests
- Integrated enterprise single sign-on with the corporate identity provider
- Optimized page speed and responsive layouts across browsers