The context

Aptimiz measures agricultural working time from machine positions. At the heart of the product, the notion of a field had grown for six years by successive additions. The model could no longer properly represent a field that changes shape or use from one season to the next.

What I did

I designed a new domain model, independent of the framework, published as an internal library and used by the API, the interface and the processing engines. Then I wrote the migration of existing data to that model, with a verification tool that compares before and after, activity by activity, and a dry-run mode by default. The switch happened without downtime.

In short

Millions of records migrated to a new model, with no interruption for users.