Multilingual Next.js platform and mobile app for 200,000 policyholders, with integration of a partner reimbursement API.
Colonna Assurances had an outdated site: non-optimized use of its health reimbursement API, responsive and performance issues, an aging interface, no multilingual support, no personalization, no ownership on Colonna's side, and no mobile app. Qadence (in charge of Colonna's digital transition) commissioned a full overhaul.
Colonna Assurances is a health insurance player whose reimbursements rely on the engine operated by a technical partner. The overhaul, started in January 2026, is led on Colonna's side by Qadence, in charge of its digital transition.
The first month: no documentation. The second: no access. So I
reverse-engineered how the partner API was used by other sites to
reconstruct internal documentation, then built a MOCK_API=true mode based on
MSW that faithfully reproduces the API's behavior. The result: we were able to
develop in parallel while waiting, and today I have a better knowledge of this
API than the partner's web service itself.
useSeenDemarches hook)pdf-lib)Today, I have ownership of all the features of the platform and the app, even those I contributed to as part of a team.
The technologies used on this mission.
Let's talk through your challenges and see how to turn your vision into maintainable, tested technical reality.