The national COVID-19 platform, past a million appointments a day.

The situation

PreventUs ran the Dutch national COVID-19 testing and vaccination programme. In the middle of the pandemic it still ran at a managed service provider.

What we built

As the platform engineer on PreventUs:

• The migration from the managed service provider to AWS, mid-pandemic and without downtime, redesigned from plain Docker to cloud-native and auto-scaling.
• All databases and applications moved to ARM (Graviton).
• Cloudsmith as the artifact platform for 15 teams and more than 500 developers, with automated onboarding and single sign-on.

What it delivered

The platform scaled past a million appointments a day, and the move to ARM cut compute cost by about 20%. With millions of users and no room for downtime, AWS was the right call at the time, and I’d make it again. When I left in 2024 the pandemic peak was over, and the platform no longer needed a dedicated platform engineer.